Operators and Functions

Question 1

Increment and decrement unary operators can be used [..] and [..]

Answer 1

Prefix and postfix

Question 2

Using [..] on an array replaces the value with ‘undefined’, leaving the index in place

Answer 2

Delete

Question 3

What is the most succinct way of finding the minimum number in an array?

Answer 3

Math.min.apply(null, arr)

Question 4

Higher order functions allow us to abstract over [..], not just values

Answer 4

Actions

Question 5

Second element in a regex/string match object

Answer 5

The first matched group

Question 6

The shorter way to create a function binding is a function [..]

Answer 6

Declaration
(
function square(x) {
return x*x;
}
)

Question 7

If an expression corresponds to a sentence fragment, then a [..] corresponds to a sentence.

Answer 7

Statement

Question 8

Postfix operators return the value [..] operating

Answer 8

Before

Question 9

Functions that automatically (when g or y modifiers are enabled) resets the lastIndex regex object property to 0 after a failure to match

Answer 9

test() and exec()

Question 10

Bindings declared with ‘let’ and ‘const’ are local to the [..] that they are declared in.

Answer 10

Block

Question 11

Array method that returns the index of the element matching the argument.

Answer 11

indexOf()

Question 12

Syntax for rest parameters or spread operator

Answer 12

…

Question 13

Function [..]s can be declared anywhere

Answer 13

Declaration

Question 14

Methods usually act on the [..] they are a property of

Answer 14

Value

Question 15

Bitwise not, which inverts all the bits in the operand and returns a number…

Answer 15

~

Question 16

A function [..] is a regular binding where the value of the binding is a function.

Answer 16

Declaration

Question 17

[..] are functions that live in properties

Answer 17

Methods

Question 18

An [..] is a symbol/sign that maps [..] to output values

Answer 18

Operator

Operandi

Question 19

If you try to destructure [..] or [..] you will get an error

Answer 19

Null

Undefined

Question 20

Date object convention - day numbers start at

Answer 20

1

Question 21

Delete does not work on any [..]

Answer 21

Non-configurable properties

Question 22

Regex (or string) method that returns a match object

Answer 22

Exec

Question 23

A fragment of code that produces a value is called an [..]

Answer 23

Expression

Question 24

What is the Regexp string replacement method in JS?

Answer 24

replace

Question 25

Every value in JS has a [..] that determines its role

Answer 25

Type

Question 26

Delete works on functions which are part of an [..] (apart from the global scope)

Answer 26

Object

Question 27

Unary operators cannot be [..]

Answer 27

Overridden

Question 28

Most values have properties, but not [..] and [..]

Answer 28

Null | Undefined

Question 29

If you omit a [..], the next line will be treated as part of the current statement.

Answer 29

Semi-colon

Question 30

This operator converts to Boolean and then negates it

Answer 30

!

Question 31

Timestamps are stored as the [..] since the start of 1970, UTC

Answer 31

Number of milliseconds

Question 32

Using delete on an object’s property will... | ... but it won’t delete it from the [..]

Answer 32

Remove it from the object (thence returning undefined when accessed) Prototype chain

Question 33

Method that returns a Boolean for a match on a regex

Answer 33

test

Question 34

Functions that operate on other functions, by taking them as arguments or returning them, are called [..] function

Answer 34

Higher-order

Question 35

Old-style variables, created using ‘var’, are [..] throughout the whole function they appear in (or else in the global scope).

Answer 35

Visible

Question 36

Return value of unary + and - on functions and objects

Answer 36

NaN

Question 37

Unary operator that yields a numeric expression

Answer 37

+

Question 38

Function [..]s start with the function keyword.

Answer 38

Declaration

Question 39

Arrays use [..] as the names of their properties

Answer 39

Numbers

Question 40

There are some named properties of arrays, e.g. [..]

Answer 40

Length

Question 41

First element in a regex/string match object

Answer 41

The whole matched string

Question 42

This operator tries to convert the operand into a number and then negates it

Answer 42

-

Question 43

Using a function as the second argument in a replace() method call, it will return..

Answer 43

A string

Question 44

When a function produces a value, it’s said to [..] that value

Answer 44

Return

Question 45

[..] means that the operator comes after the operand

Answer 45

Postfix

Question 46

[..] operators are more efficient than standard JS function calls

Answer 46

Unary

Question 47

A [..] is a piece of code wrapped in a value

Answer 47

Function

Question 48

What key function in JS is ‘select’ in Ruby?

Answer 48

filter

Question 49

When a regex/string group matches several times, [..] is returned in the match object

Answer 49

Only the first match

Question 50

Function that converts an expression to JSON string

Answer 50

JSON.stringify

Question 51

Global variable to reference the full match after a ‘replace’ call

Answer 51

$&

Question 52

This method returns the index of the first regex match, or -1 if there wasn’t one

Answer 52

search

Question 53

Function [..]s don’t require a semi-colon afterwards

Answer 53

Declarations

Question 54

Regex object property that specifies the character position immediately following the last match

Answer 54

lastIndex

Question 55

Using a function as the second argument in a replace() method call, [..] will be passed as arguments to that function

Answer 55

The matched groups (and the whole match)

Question 56

JSON strings - [..] JavaScript, encoded so that it can be stored or sent

Answer 56

Serialized | Converted into a flat description

Question 57

Date object convention - months start at

Answer 57

0

Question 58

JSON stands for

Answer 58

JavaScript Object Notation

Question 59

Unary operator that discards a return value of an expression

Answer 59

Void

Question 60

Regex#test and Regex#exec will use this readable/writable property of the Regex object as a starting point for the match

Answer 60

lastIndex

Question 61

Function that tests whether any element of an array matches a given predicate function

Answer 61

Some

Question 62

Method on a date object that returns that number of milliseconds relative to 1970

Answer 62

getTime()

Question 63

Function that finds the position (in an array) of the first element that matches a predicate

Answer 63

indexOf()

Question 64

The collection of bindings and their values that exist at any given time is known as the [..]

Answer 64

Environment

Question 65

A program is a list of

Answer 65

Statements

Question 66

Function that parses a JSON string back into JS

Answer 66

JSON.parse

Question 67

When a regex/string returns a match object, unmatched groups in the array will hold an [..] value

Answer 67

Undefined

Question 68

In Regex, using this after a quantifier makes it lazy instead of greedy

Answer 68

?

Question 69

Modifier for a regex to make it global

Answer 69

g

Question 70

Prefix means that the operator comes [..] the operand

Answer 70

Before

Question 71

All [..] in JSON strings have to be surrounded by double quotes.

Answer 71

Properties

Question 72

A [..] operator is one that takes a single operand/argument and performs an operation.

Answer 72

Unary

Question 73

[..] operators return the value after the operation

Answer 73

Prefix

Question 74

A lazy quantifier consumes the [..] set of characters before returning a match

Answer 74

Smallest

Question 75

Function that returns true when every element in an array returns true for a predicate function

Answer 75

Every