a) <\/div>\n
function myFunction() {} <\/code><\/pre>\nb) <\/div>\n
let myFunction = function() {};<\/code><\/pre>\nc) <\/div>\n
const myFunction = () => {};<\/code><\/pre>\nd) All of the above <\/div>\n
Click to View Answer and Explanation<\/button>\n\n
Answer: <\/h3>\n d) All of the above <\/div>\n
Explanation: <\/h3>\n All three options are valid ways to define functions in JavaScript. Option a) is the traditional function declaration, b) is a function expression, and c) is an arrow function (introduced in ES6).<\/div>\n<\/div>\n
2. What keyword is used to return a value from a JavaScript function? <\/h2>\na) value <\/div>\n
b) result <\/div>\n
c) return <\/div>\n
d) output <\/div>\n
Click to View Answer and Explanation<\/button>\n\n
Answer: <\/h3>\n c) return <\/div>\n
Explanation: <\/h3>\n The
return<\/i> keyword is used to send a value back from the function to the caller. When the return<\/i> statement is encountered, the function’s execution stops, and the value following the return is returned as the result of the function.<\/div>\n<\/div>\n3. How do you call a JavaScript function named myFunction? <\/h2>\na) call myFunction(); <\/div>\n
b) run myFunction(); <\/div>\n
c) myFunction(); <\/div>\n
d) execute myFunction(); <\/div>\n
Click to View Answer and Explanation<\/button>\n\n
Answer: <\/h3>\n c) myFunction(); <\/div>\n
Explanation: <\/h3>\n To call a function in JavaScript, you simply use the function’s name followed by parentheses
()<\/i>.<\/div>\n<\/div>\n4. What is a callback function in JavaScript? <\/h2>\na) A function that performs asynchronous tasks. <\/div>\n
b) A function that is called at the end of the program’s execution. <\/div>\n
c) A function that is passed as an argument to another function and is executed inside that function. <\/div>\n
d) A function that is used for error handling. <\/div>\n
Click to View Answer and Explanation<\/button>\n\n
Answer: <\/h3>\n c) A function that is passed as an argument to another function and is executed inside that function.<\/div>\n
Explanation: <\/h3>\n A callback function is a function that is passed as an argument to another function and is executed inside that function. It allows for better control of the flow of asynchronous code in JavaScript.<\/div>\n<\/div>\n
5. What is a “recursive” function in JavaScript? <\/h2>\na) A function that includes a loop. <\/div>\n
b) A function that calls itself within its own body. <\/div>\n
c) A function that takes multiple arguments. <\/div>\n
d) A function that executes a callback function. <\/div>\n
Click to View Answer and Explanation<\/button>\n\n
Answer: <\/h3>\n b) A function that calls itself within its own body. <\/div>\n
Explanation: <\/h3>\n A recursive function is a function that calls itself during its execution, either directly or indirectly, to solve a problem or perform a repetitive task.
<\/div>\n<\/div>\n
6. What is a “closure” in JavaScript? <\/h2>\na) A function that is stored as a property of an object. <\/div>\n
b) A function that can be accessed globally from any part of the code. <\/div>\n
c) A function that is defined inside another function and has access to its outer function’s variables. <\/div>\n
d) A function that takes an unlimited number of arguments. <\/div>\n
Click to View Answer and Explanation<\/button>\n\n
Answer: <\/h3>\n c) A function that is defined inside another function and has access to its outer function’s variables.<\/div>\n
Explanation: <\/h3>\n A
closure<\/i> is a function that retains access to variables from its containing (enclosing) function’s scope, even after the outer function has finished executing.<\/div>\n<\/div>\n7. Which method can be used to execute a function after a specified time interval? <\/h2>\na) executeAfterTime() <\/div>\n
b) setInterval() <\/div>\n
c) executeEvery() <\/div>\n
d) setTimeout() <\/div>\n
Click to View Answer and Explanation<\/button>\n\n
Answer: <\/h3>\n d) setTimeout() <\/div>\n
Explanation: <\/h3>\n The
setTimeout()<\/i> method is used to execute a function after a specified delay (time interval) in milliseconds.<\/div>\n<\/div>\n8. How can you immediately invoke an anonymous function in JavaScript? <\/h2>\na) function() { }(); <\/div>\n
b) function { } (); <\/div>\n
c) function { } (); <\/div>\n
d) (function() { })(); <\/div>\n
Click to View Answer and Explanation<\/button>\n\n
Answer: <\/h3>\n d) (function() { })(); <\/div>\n
Explanation: <\/h3>\n To immediately invoke an anonymous function, enclose the function declaration in parentheses and add
()<\/i> at the end to call it.<\/div>\n<\/div>\n9. What will be the output of the following code?<\/h2>\nfunction greet() {\n console.log("Hello!");\n}\n\nvar sayHello = greet;\nsayHello();<\/code><\/pre>\n a) Hello! <\/div>\n
b) sayHello <\/div>\n
c) function greet() { console.log(“Hello!”); } <\/div>\n
d) undefined <\/div>\n
Click to View Answer and Explanation<\/button>\n\n
Answer: <\/h3>\n a) Hello! <\/div>\n
Explanation: <\/h3>\n The variable
sayHello<\/i> is assigned the value of the greet<\/i> function. When sayHello()<\/i> is called, it executes the greet<\/i> function and logs “Hello!” to the console.<\/div>\n<\/div>\n10. How do arrow functions differ from regular functions in ES6? <\/h2>\na) Arrow functions have shorter syntax than regular functions. <\/div>\n
b) Arrow functions do not have their own this value. <\/div>\n
c) Arrow functions cannot be used as methods in objects. <\/div>\n
d) All of the above <\/div>\n
Click to View Answer and Explanation<\/button>\n\n
Answer: <\/h3>\n d) All of the above <\/div>\n
Explanation: <\/h3>\n Arrow functions in ES6 have shorter syntax, do not have their own
this<\/i> value (they inherit it from the surrounding scope), and cannot be used as constructors or methods in objects.<\/div>\n<\/div>\nConclusion<\/h2>\n Congratulations on completing the JavaScript Functions Quiz! Functions are the building blocks of JavaScript programming, allowing you to write modular and maintainable code. A solid understanding of functions is crucial for mastering JavaScript development. Continue practicing and exploring real-world applications to sharpen your skills further. Happy coding!<\/div>\n