Question 1

Console.log()

Accepted Answer

The ______ method is used to log or print messages to the console.

console.log('Hi there!');
// Prints: Hi there!

Question 2

Javascript

Accepted Answer

________ is a programming language that powers the dynamic behavior on most websites. Alongside HTML and CSS, it is a core technology that makes the web run.

Question 3

Method

Accepted Answer

________ return information about an object, and are called by appending an instance with a period " . " the method name, and parentheses.

// Returns a number between 0 and 1
Math.random();

Question 4

Libraries

Accepted Answer

_______ contain methods that can be called by appending the library name with a period ., the method name, and a set of parentheses.

Math.random();

Question 5

Numbers

Accepted Answer

_______  are a primitive data type. They include the set of all integers and floating point numbers.

let amount = 6;
let price = 4.99;

Question 6

The 5 primitive data types

Accepted Answer

Numbers, Strings, Boolean, Null and Undefined

Question 7

string.length

Accepted Answer

The .length property of a string returns the number of characters that make up the string.

Question 8

Boolean

Accepted Answer

______  are a primitive data type. They can be either true or false.

Question 9

Math.random()

Accepted Answer

The _______ function returns a floating-point, random number in the range from 0 (inclusive) up to but not including 1.

console.log(Math.random());
// Prints: 0 - 0.9

Question 10

Math.floor()

Accepted Answer

This function returns the largest integer less than or equal to the given number.

console.log(Math.floor(5.95)); 
// Prints: 5

Question 11

Single Line Comment

Accepted Answer

______ comments are created with two consecutive forward slashes //.

// This line will denote a comment

Question 12

Null

Accepted Answer

is a primitive data type. It represents the intentional absence of value. 

let x = null;

Question 13

Strings

Accepted Answer

_____ are a primitive data type. They are any grouping of characters (letters, spaces, numbers, or symbols) surrounded by single quotes ' or double quotes ".

let single = 'Wheres my bandit hat?';
let double = "Wheres my bandit hat?";

Question 14

Arithmetic  Operators

Accepted Answer

+ addition
- subtraction
* multiplication
/ division
% modulo
** exponents
++ increment
-- decrement

Question 15

Multi-Line Comments

Accepted Answer

These comments are created by surrounding the lines with /* at the beginning and */ at the end. Comments are good ways for a variety of reasons like explaining a code block or indicating some hints, etc.

/*  
The below must be 
changed. 
*/

Question 16

Assignment Operators

Accepted Answer

This assigns a value to its left operand based on the value of its right.

+= add, -= subtract, *= multi, /= division

let number = 100;

// Both statements will add 10
number = number + 10;
number += 10;

console.log(number); 
// Prints: 120

Question 17

Variables  pt.1

Accepted Answer

______ are used whenever there’s a need to store a piece of data. A variable contains data that can be used in the program elsewhere. Using variables also ensures code re-usability since it can be used to replace the same value in multiple places.

Question 18

Variables pt. 2

Accepted Answer

______ are used whenever there’s a need to store a piece of data.

const currency = '$';
let userIncome = 85000; 

console.log(currency + userIncome + ' is more than the average income.');
// Prints: $85000 is more than the average income.

Question 19

Undefined

Accepted Answer

_______ is a primitive JavaScript value that represents lack of defined value. Variables that are declared but not initialized to a value will have the value______.

var a;

console.log(a); 
// Prints: undefined

Question 20

Declaring a Variable

Accepted Answer

Any of these three keywords can be used along with a variable name:

var is used in pre-ES6 versions of JavaScript.
let is the preferred way to _______ when it can be reassigned.
const is the preferred way to _______ with a constant value.

Question 21

Var

Accepted Answer

____ declarations, wherever they occur, are processed before any code is executed. This is called hoisting.

The scope of a variable declared is global.

Question 22

Let

Accepted Answer

_____creates a local variable in JavaScript & can be re-assigned. ______ allows you to declare variables that are limited to the scope of a block statement, or expression on which it is used, unlike the var keyword.

Question 23

Const

Accepted Answer

______ are block-scoped, much like variables defined using the let keyword. The value of a constant can't be changed through reassignment, and it can't be redeclared.

Question 24

Function

Accepted Answer

Declares a function with the specified parameters.

Question 25

Return

Accepted Answer

Specifies the value to be returned by a function.

Question 26

Class

Accepted Answer

Declares a class.

Question 27

For Loop

Accepted Answer

Creates a loop that consists of three optional expressions, enclosed in parentheses and separated by semicolons, followed by a statement executed in the loop.

let str = '';

_____ (let i = 0; i < 9; i++) {
  str = str + i;
}

Question 28

While Loop

Accepted Answer

Creates a loop that executes a specified statement as long as the test condition evaluates to true. The condition is evaluated before executing the statement.

let n = 0;

_______ (n < 3) {
  n++;
}

console.log(n);
// expected output: 3

Question 29

If Else

Accepted Answer

If condition is truthy = executes. If falsy, another state can be executed.

function testNum(a) {
  let result;
  if (a > 0) {
    result = 'positive';
  } else {
    result = 'NOT positive';
  }
  return result;
}

console.log(testNum(-5));

Question 30

Object

Accepted Answer

This class represents one of JavaScript's data types. It is used to store various keyed collections and more complex entities.

Question 31

Equality Operators

Accepted Answer

==
!=
===
!==

Question 32

Relational Operators

Accepted Answer

in instanceof < > <= >=

Question 33

Binary Logical Operators

Accepted Answer

&& - and
|| - or
! - not

Question 34

Function Expression

Accepted Answer

The function keyword can be used to define a function inside an expression.

const getRectArea = function(width, height) {
  return width * height;
};

console.log(getRectArea(3, 4));
// expected output: 12

Question 35

Function Declaration

Accepted Answer

This (function statement) defines a function with the specified parameters.

function calcRectArea(width, height) {
  return width * height;
}

console.log(calcRectArea(5, 6));
// expected output: 30

Question 36

NaN

Accepted Answer

The global ______ property is a value representing Not-A-Number.

Question 37

String Concatenation

Accepted Answer

Multiple strings can be put together using the + operator.

let service = 'credit card';
let month = 'May 30th'; 
let displayText = 'Your ' + service  + ' bill is due on  ' +  month + '.';

Question 38

Arrays

Accepted Answer

Lists of ordered, stored data. They can hold items that are of any data type. ______ are created by using square brackets and commas.

// An array containing different data types
const mixedArray = [1, 'chicken', false];

Question 39

Method    .push()

Accepted Answer

Adding one or more elements to the end of an array.

// Adding multiple elements:
const numbers = [1, 2];
numbers.push(3, 4, 5);

console.log(numbers)
// [1, 2, 3, 4, 5 ]

Question 40

Method     .pop()

Accepted Answer

This method removes the last element from an array and returns that element.

const ingredients = ['eggs', 'flour', 'chocolate'];

const poppedIngredient = ingredients.pop(); // 'chocolate'
console.log(ingredients); // ['eggs', 'flour']

Question 41

Mutable

Accepted Answer

JavaScript arrays are _____ meaning that the values they contain can be changed.

Question 42

Logical Not Operator

Accepted Answer

The ________ ! can be used to do one of the following:

Invert a Boolean value.
Invert the truthiness of non-Boolean values.

Javascript Vocab

Just the basic concepts and definitions for basic Javascript

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