mix-questions.js

[
    {
      "questionText": " JSX stands for _____.?",
      "options": [
        {
          "option": "JSON",
          "isCorrect": false
        },
        {
          "option": "JSON XML",
          "isCorrect": false
        },
        {
          "option": "JavaScript and AngularJS",
          "isCorrect": true
        },
        {
          "option": "All of the mentioned above",
          "isCorrect": false
        }
      ],
      "correctOptions": 1,
      "explanation": "JSX stands for JavaScript XML.",
      "code": "",
      "questionNumber": 1,
      "inputType": "radio",
      "questionType": "react",
      "difficultyLevel": "beginner"
    },
    {
        "questionText": "Consider the below function – which is the correct syntax of arrow function?",
        "options": [
          {
            "option": "Msg = () => {return 'Good Morning'}",
            "isCorrect": false
          },
          {
            "option": "Msg = () => 'Good Morning';",
            "isCorrect": false
          },
          {
            "option": "Both A. and B.",
            "isCorrect": true
          },
          {
            "option": "None of the above",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "In ES6 – Below given both of the syntaxes are correct of arrow function",
        "code": "",
        "questionNumber": 2,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "beginner"
      },
      {
        "questionText": " Complete the below given arrow function.",
        "options": [
          {
            "option": "()",
            "isCorrect": false
          },
          {
            "option": "=>",
            "isCorrect": false
          },
          {
            "option": "()>",
            "isCorrect": false
          },
          {
            "option": "() =>",
            "isCorrect": true
          }
        ],
        "correctOptions": 1,
        "explanation": "The correct arrow function is: Msg = () => 'Hi, there!';",
        "code": "Msg = ____ 'Hi, there!';",
        "questionNumber": 3,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "beginner"
      },
      {
        "questionText": "Which method is used to generate lists?",
        "options": [
          {
            "option": "map()",
            "isCorrect": true
          },
          {
            "option": "generate()",
            "isCorrect": false
          },
          {
            "option": "new()",
            "isCorrect": false
          },
          {
            "option": "maps()",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "The map() method is used to generate lists in React ES6.",
        "code": "",
        "questionNumber": 4,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "beginner"
      },
      {
        "questionText": "In ReactJS, what is State?",
        "options": [
          {
            "option": "It's a temporary storage of the elements",
            "isCorrect": false
          },
          {
            "option": "It's a state of the execution of the ReactJS application",
            "isCorrect": false
          },
          {
            "option": "It's an internal storage of the components",
            "isCorrect": true
          },
          {
            "option": "All of the above",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "In ReactJS, the State is an internal storage of the components.",
        "code": "",
        "questionNumber": 5,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "beginner"
      },
      {
        "questionText": " ReactJS uses _____ to increase performance",
        "options": [
          {
            "option": "Virtual DOM",
            "isCorrect": true
          },
          {
            "option": "Real DOM",
            "isCorrect": false
          },
          {
            "option": " Both A and B are true.",
            "isCorrect": false
          },
          {
            "option": " None of the above",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "ReactJS uses virtual DOM to increase performance",
        "code": "",
        "questionNumber": 6,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "intermediate"
      },
      {
        "questionText": " How many elements does a React component return?",
        "options": [
          {
            "option": "1 element",
            "isCorrect": false
          },
          {
            "option": " 2 elements",
            "isCorrect": false
          },
          {
            "option": "Many elements",
            "isCorrect": false
          },
          {
            "option": "None of the above",
            "isCorrect": true
          }
        ],
        "correctOptions": 1,
        "explanation": "A React component returns multiple items.",
        "code": "",
        "questionNumber": 7,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "intermediate"
      },
      {
        "questionText": " What are the limits of ReactJS?",
        "options": [
          {
            "option": "React is only for the View layer of the app, so we still need the help of other technologies to get a full set of tools for development.",
            "isCorrect": false
          },
          {
            "option": "React uses inline and JSX templates. It may seem annoying for some developers",
            "isCorrect": false
          },
          {
            "option": "React library is too large",
            "isCorrect": false
          },
          {
            "option": "All the answers are true",
            "isCorrect": true
          }
        ],
        "correctOptions": 1,
        "explanation": "React is just a view library, not a full framework,There is a learning curve for beginners who are new to web development,Integrating React into a traditional MVC framework requires some additional configuration,The code complexity increases with inline templating and JSX,Too many smaller components leading to over engineering or boilerplate",
        "code": "",
        "questionNumber": 8,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "intermediate"
      },
      {
        "questionText": "State in react is a ________",
        "options": [
          {
            "option": "Permanent storage",
            "isCorrect": false
          },
          {
            "option": " Internal component storage",
            "isCorrect": true
          },
          {
            "option": "Both A and B are true.",
            "isCorrect": false
          },
          {
            "option": "None of the above",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "State in react is an internal storage of the component.",
        "code": "",
        "questionNumber": 9,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "intermediate"
      },
      {
        "questionText": "Props are __________ in other components",
        "options": [
          {
            "option": " Injected",
            "isCorrect": false
          },
          {
            "option": "methods",
            "isCorrect": true
          },
          {
            "option": "Both A and B are true.",
            "isCorrect": false
          },
          {
            "option": "None of the above",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "“Props” is a special keyword in React, which stands for properties and is used to pass data from one component to another. But the important part here is that data with props is transmitted in a one direction.In addition, the data in Props is read-only, which means that the data coming from the parent must not be modified by the child components.",
        "code": "",
        "questionNumber": 10,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "intermediate"
      },
      {
        "questionText": "What is react.js in MVC",
        "options": [
          {
            "option": " Middleware",
            "isCorrect": false
          },
          {
            "option": " Model",
            "isCorrect": true
          },
          {
            "option": "View",
            "isCorrect": false
          },
          {
            "option": "Controller",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "React.js is considered as the View in MVC (Model View Controller).",
        "code": "",
        "questionNumber": 11,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "advanced"
      },
      {
        "questionText": "Keys are given to a list of elements in react. These keys should be -",
        "options": [
          {
            "option": " Do not requires to be unique",
            "isCorrect": false
          },
          {
            "option": " Unique in the DOM",
            "isCorrect": false
          },
          {
            "option": "Unique among the siblings only",
            "isCorrect":true
          },
          {
            "option": "All of the above",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "Keys are given to a list of elements in react. These keys should be unique among the siblings only.",
        "code": "",
        "questionNumber": 12,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "advanced"
      },
      {
        "questionText": "React is mainly used for building ..................",
        "options": [
          {
            "option": " Database",
            "isCorrect": false
          },
          {
            "option": "User interface",
            "isCorrect": true
          },
          {
            "option": " Connectivity",
            "isCorrect": false
          },
          {
            "option": " Design platform",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "React is mainly used for building user interfaces.",
        "code": "",
        "questionNumber": 13,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "advanced"
      },
      {
        "questionText": "useLayoutEffect function is used to ..............",
        "options": [
          {
            "option": "complete the update",
            "isCorrect": false
          },
          {
            "option": "optimize for all devices",
            "isCorrect": false
          },
          {
            "option": "change the layout of the screen",
            "isCorrect": false
          },
          {
            "option": "when we need the browser to paint before effectors",
            "isCorrect": true
          }
        ],
        "correctOptions": 1,
        "explanation": "In react.js useLayoutEffect function is used, when we need the browser to paint before effectors.",
        "code": "",
        "questionNumber": 14,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "advanced"
      },
      {
        "questionText": "React components are saved in ............. directory",
        "options": [
          {
            "option": "js/components",
            "isCorrect": true
          },
          {
            "option": " components/js",
            "isCorrect": false
          },
          {
            "option": " vendor/components",
            "isCorrect": false
          },
          {
            "option": "None of the above",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": " React components are saved in js/components directory.",
        "code": "",
        "questionNumber": 15,
        "inputType": "radio",
        "questionType": "react",
        "difficultyLevel": "advanced"
      },
      {
        "questionText": "Which of the following variables takes precedence over the others if the names are the same?",
        "options": [
          {
            "option": "Global variable",
            "isCorrect": false
          },
          {
            "option": "The local element",
            "isCorrect": true
          },
          {
            "option": "The two of the above",
            "isCorrect": false
          },
          {
            "option": "None of the above",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "In JavaScript, the local variable takes precedence over the global variable if the name of both local and global variables is the same.",
        "code": "",
        "questionNumber": 16,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "beginner"
      },

      {
        "questionText": "What is the name of the statement that is used to exit or end a loop?",
        "options": [
          {
            "option": "Falter statement",
            "isCorrect": false
          },
          {
            "option": "Close statement",
            "isCorrect": false
          },
          {
            "option": "Break statement",
            "isCorrect": true
          },
          {
            "option": "Conditional statement",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "Break in aloop will exit the loop. It stops the execution",
        "code": "",
        "questionNumber": 17,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "beginner"
      },

      {
        "questionText": "What elements are used to test for TRUE or False values stored in variables?",
        "options": [
          {
            "option": "Conditional statements.",
            "isCorrect": true
          },
          {
            "option": "Comparison and logical operators",
            "isCorrect": false
          },
          {
            "option": "Trigger readers.",
            "isCorrect": false
          },
          {
            "option": "RegExp or Regular Expressions.",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "Operators are used to test TRUE or FALSE",
        "code": "",
        "questionNumber": 18,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "beginner"
      },

      {
        "questionText": "What is the object called that lets you work with both dates and time-related data?",
        "options": [
          {
            "option": "Dates",
            "isCorrect": true
          },
          {
            "option": "Time field",
            "isCorrect": false
          },
          {
            "option": "Clock",
            "isCorrect": false
          },
          {
            "option": "Time-warp",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "Dates lets you work with both dates and time-related data",
        "code": "",
        "questionNumber": 19,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "beginner"
      },

      {
        "questionText": "In JavaScript, what is a block of code called that is used to perform a specific task?",
        "options": [
          {
            "option": "String",
            "isCorrect": false
          },
          {
            "option": "Variable",
            "isCorrect": false
          },
          {
            "option": "Declaration",
            "isCorrect": false
          },
          {
            "option": "Function",
            "isCorrect": true
          }
        ],
        "correctOptions": 1,
        "explanation": " Function is a block of code called that is used to perform a specific task",
        "code": "",
        "questionNumber": 20,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "beginner"
      },
      {
        "questionText": "What is the output?",
        "options": [
          {
            "option": "20",
            "isCorrect": true
          },
          {
            "option": "10",
            "isCorrect": false
          },
          {
            "option": "30",
            "isCorrect": false
          },
          {
            "option": "undefined",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "the previous initialization is overwritten by the current initialization. So the value is 20",
        "code": "let a = 10;\n var a = 20; \n console.log(a);",
        "questionNumber": 21,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "intermediate"
      },

      {
        "questionText": "Find the sum of all elements/numbers of a given array?",
        "options": [
          {
            "option": "38",
            "isCorrect": true
          },
          {
            "option": " 37",
            "isCorrect": false
          },
          {
            "option": "36",
            "isCorrect": false
          },
          {
            "option": "35",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "reducer method stores the prev and curr values and returns the sum in array",
        "code": "var arr = [1, 2, 5, 10, 20]; \n var sum = arr.reduce((a, i) => {\n return a + i;\n });\n document.write(sum);",
        "questionNumber": 22,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "intermediate"
      },

      {
        "questionText": "What will be output of following?",
        "options": [
          {
            "option": "string string undefined undefined",
            "isCorrect": false
          },
          {
            "option": "undefined string undefined object",
            "isCorrect": false
          },
          {
            "option": " undefined undefined undefined undefined",
            "isCorrect": false
          },
          {
            "option": "undefined object undefined string",
            "isCorrect": true
          }
        ],
        "correctOptions": 1,
        "explanation": "Data types of js concepts",
        "code": "console.log(typeof undefined);\n console.log(typeof null); \n console.log(typeof NULL); \n console.log(typeof typeof 1);",
        "questionNumber": 23,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "intermediate"
      },

      {
        "questionText": "React components are saved in ............. directory",
        "options": [
          {
            "option": "5 4 5",
            "isCorrect": false
          },
          {
            "option": "5 3 5",
            "isCorrect": true
          },
          {
            "option": "5 4 4",
            "isCorrect": false
          },
          {
            "option": "5 3 4",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "The value of a is initalised to b first and the it is incremented. so b=3 and when the value of c is initialed , a is incremented 2 times, so the value of c is 5",
        "code": "let a=3; \n let b=a++; \n let c=++a; \n console.log(a,b,c)",
        "questionNumber": 24,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "intermediate"
      },

      {
        "questionText": "React components are saved in ............. directory",
        "options": [
          {
            "option": "js/components",
            "isCorrect": true
          },
          {
            "option": " components/js",
            "isCorrect": false
          },
          {
            "option": " vendor/components",
            "isCorrect": false
          },
          {
            "option": "None of the above",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": " React components are saved in js/components directory.",
        "code": "",
        "questionNumber": 25,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "intermediate"
      },

      {
        "questionText": "Write the output of the following javascript programs?",
        "options": [
          {
            "option": "4",
            "isCorrect": false
          },
          {
            "option": "5",
            "isCorrect": true
          },
          {
            "option": "3",
            "isCorrect": false
          },
          {
            "option": "0",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": " It will reference the last value stored in i, which was 5.",
        "code": "for (var i = 0; i < 5; i++) \n {setTimeout(() => { \n console.log(i); \n }, 1000);}",
        "questionNumber": 26,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "advanced"
      },

      {
        "questionText": "Why do we need Callbacks?",
        "options": [
          {
            "option": "Callbacks are a way to make sure doesnot wait for any codes",
            "isCorrect": false
          },
          {
            "option": " Callbacks are a way to make sure certain code execute until other code has already finished execution.",
            "isCorrect": false
          },
          {
            "option": "Callbacks are a way to make sure  code  execute line by line",
            "isCorrect": false
          },
          {
            "option": "Callbacks are a way to make sure certain code doesn't execute until other code has already finished execution.",
            "isCorrect": true
          }
        ],
        "correctOptions": 1,
        "explanation": "Callbacks are a way to make sure certain code doesn't execute until other code has already finished execution.",
        "code": "",
        "questionNumber": 27,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "advanced"
      },

      {
        "questionText": "What is Promise in JavaScript?",
        "options": [
          {
            "option": "can be returned asynchronously from an synchronous function.",
            "isCorrect": false
          },
          {
            "option": "can be returned synchronously from an asynchronous function.",
            "isCorrect": true
          },
          {
            "option": "can return function.",
            "isCorrect": false
          },
          {
            "option": "None of the above",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "A promise is an object which can be returned synchronously from an asynchronous function.",
        "code": "",
        "questionNumber": 28,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "advanced"
      },

      {
        "questionText": "What is Hoisting in JavaScript?",
        "options": [
          {
            "option": "variables can be initialized",
            "isCorrect": false
          },
          {
            "option": "a variable can be declared after it has been used",
            "isCorrect": false
          },
          {
            "option": "variables and function declarations are moved to the top of their scope before code execution.",
            "isCorrect": true
          },
          {
            "option": "None of the above",
            "isCorrect": false
          }
        ],
        "correctOptions": 1,
        "explanation": "Hoisting is JavaScript's default behavior of moving all declarations to the top of the current scope (to the top of the current script or the current function).",
        "code": "",
        "questionNumber": 29,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "advanced"
      },

      {
        "questionText": "What is the output of the following?",
        "options": [
          {
            "option": "undefined and 5",
            "isCorrect": false
          },
          {
            "option": "undefined",
            "isCorrect": false
          },
          {
            "option": "10",
            "isCorrect": false
          },
          {
            "option": "5 and undefined",
            "isCorrect": true
          }
        ],
        "correctOptions": 1,
        "explanation": "JavaScript only hoists declarations, not initializations.Because variable y is not initialized before it is being used.",
        "code": "var x = 5; \n console.log('value is ' + x + ' and '+ y); \n var y = 10; ",
        "questionNumber": 30,
        "inputType": "radio",
        "questionType": "javascript",
        "difficultyLevel": "advanced"
      },




]