JavaScript Arrays and Functions Quiz
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Questions and Answers

In JavaScript, what is hoisting?

  • Treating a parameter as undefined if not passed a value in the arguments list
  • Moving all variable and function declarations to the top of the current scope (correct)
  • Accessing the arguments object to access the values passed to a function
  • Passing additional arguments to a function

    • What happens if there is a mismatch between the argument list and parameter list in JavaScript functions?

  • It gives an error
  • It automatically adjusts the parameter list to match the argument list
  • The parameter that is not passed a value is treated as undefined
  • The function still executes without any errors (correct)

    • What happens to variables and functions declared with let or const in JavaScript's hoisting behavior?

  • They are hoisted but not initialized
  • They are hoisted only if they are constants
  • They are hoisted to the top of the current scope
  • They are not hoisted (correct)

    • What is the purpose of the arguments object in JavaScript functions?

    <p>To access additional arguments passed to the function</p> Signup and view all the answers

    What is the correct way to access values passed to a JavaScript function using an array?

    <p>Using the args array</p> Signup and view all the answers

    What does JavaScript do with variables and function declarations by default?

    <p>Hoist them to the top of the current scope</p> Signup and view all the answers

    In JavaScript, how are arrays created using the 'new Array' method?

    <p>let arr = new Array(10, 20)</p> Signup and view all the answers

    What is the index of the last element in a JavaScript array of length n?

    <p>n-1</p> Signup and view all the answers

    How can you create a literal array in JavaScript?

    <p>var alist = [1, 'ii', 'gamma', '4']</p> Signup and view all the answers

    What happens when you modify the length property of a JavaScript array at runtime?

    <p>The array length property affects the number of defined values in the array</p> Signup and view all the answers

    What is the correct syntax for defining a function in JavaScript?

    <p>function function_name(parameter)</p> Signup and view all the answers

    What type of index does the 'for-in' loop in JavaScript return when used with an array?

    <p>String</p> Signup and view all the answers

    Study Notes

    Hoisting in JavaScript

    • Hoisting is a behavior in JavaScript where variables and functions are moved to the top of their scope, regardless of their placement in the code.

    Function Arguments and Parameters

    • A mismatch between the argument list and parameter list in JavaScript functions does not cause an error; instead, excess arguments are ignored, and excess parameters are set to undefined.

    Let and Const in Hoisting

    • Variables and functions declared with let or const are not hoisted, unlike those declared with var; instead, they are placed in a "temporal dead zone" until they are declared.

    The Arguments Object

    • The arguments object in JavaScript functions is an array-like object that contains the values passed to the function.

    Accessing Function Arguments

    • To access values passed to a JavaScript function using an array, you can use the arguments object or the rest parameter syntax (...args).

    Default Behavior

    • By default, JavaScript moves variables and function declarations to the top of their scope, but this can be overridden by using let or const.

    Creating Arrays

    • Arrays can be created using the new Array method, but this is not recommended; instead, use the literal array syntax ([]).
    • Arrays can also be created using the literal array syntax, where each element is separated by a comma.

    Array Index

    • The index of the last element in a JavaScript array of length n is n - 1.

    Modifying Array Length

    • When you modify the length property of a JavaScript array at runtime, elements are added or removed from the end of the array accordingly.

    Defining Functions

    • The correct syntax for defining a function in JavaScript is function name(parameters) { code } or const name = function(parameters) { code }.

    For-In Loop

    • The for-in loop in JavaScript returns a string index when used with an array, not a numeric index.

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    Description

    Test your knowledge of JavaScript arrays and functions with this quiz. Learn about creating arrays, indexing elements, using the new Array method, and creating literal arrays with square brackets.

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