Array API Flashcards

Memorizing most useful Array methods on JavaScript

1
Q

Returns a new array comprised of this array joined with other array(s) and/or value(s).

A

array.concat(value1, value2, …, valueN)

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2
Q

Tests whether all elements in the array pass the test implemented by the provided function.

A

array.every(callback[, thisObject])

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3
Q

Creates a new array with all elements that pass the test implemented by the provided function.

A

array.filter(callback[, thisObject])

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4
Q

Executes a provided function once per array element.

A

array.forEach(callback[, thisArg])

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5
Q

Returns the first index at which a given element can be found in the array, or -1 if it is not present.

A

array.indexOf(searchElement[, fromIndex])

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6
Q

Joins all elements of an array into a string.

A

array.join(separator)

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7
Q

Returns the last index at which a given element can be found in the array, or -1 if it is not present. The array is searched backwards, starting at fromIndex.

A

array.lastIndexOf(searchElement[, fromIndex])

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8
Q

Creates a new array with the results of calling a provided function on every element in this array.

A

array.map(callback[, thisArg])

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9
Q

Removes the last element from an array and returns that element.

A

array.pop()

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10
Q

Mutates an array by appending the given elements and returning the new length of the array.

A

array.push(element1, …, elementN)

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11
Q

Reverses an array in place. The first array element becomes the last and the last becomes the first.

A

array.reverse()

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12
Q

Removes the first element from an array and returns that element. This method changes the length of the array.

A

array.shift()

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13
Q

Returns a one-level deep copy of a portion of an array.

A

array.slice(begin[, end])

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14
Q

Sorts the elements of an array in place and returns the array.

A

array.sort([compareFunction])

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15
Q

Changes the content of an array, adding new elements while removing old elements.

A

array.splice(index , howMany[, element1[, …[, elementN]]]) array.splice(index[, howMany[, element1[, …[, elementN]]]])

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16
Q

Adds one or more elements to the beginning of an array and returns the new length of the array.

A

arrayName.unshift(element1, …, elementN)

17
Q

array.concat(value1, value2, …, valueN)

A

Returns a new array comprised of this array joined with other array(s) and/or value(s).

18
Q

array.every(callback[, thisObject])

A

Tests whether all elements in the array pass the test implemented by the provided function.

19
Q

array.filter(callback[, thisObject])

A

Creates a new array with all elements that pass the test implemented by the provided function.

20
Q

array.forEach(callback[, thisArg])

A

Executes a provided function once per array element.

21
Q

array.indexOf(searchElement[, fromIndex])

A

Returns the first index at which a given element can be found in the array, or -1 if it is not present.

22
Q

array.join(separator)

A

oins all elements of an array into a string.

23
Q

array.lastIndexOf(searchElement[, fromIndex])

A

Returns the last index at which a given element can be found in the array, or -1 if it is not present. The array is searched backwards, starting at fromIndex.

24
Q

array.map(callback[, thisArg])

A

Creates a new array with the results of calling a provided function on every element in this array.

25
Q

array.pop()

A

Removes the last element from an array and returns that element.

26
Q

array.push(element1, …, elementN)

A

Mutates an array by appending the given elements and returning the new length of the array.

27
Q

array.reverse()

A

Reverses an array in place. The first array element becomes the last and the last becomes the first.

28
Q

array.shift()

A

Removes the first element from an array and returns that element. This method changes the length of the array.

29
Q

array.slice(begin[, end])

A

Returns a one-level deep copy of a portion of an array.

30
Q

array.sort([compareFunction])

A

Sorts the elements of an array in place and returns the array.

31
Q

array.splice(index , howMany[, element1[, …[, elementN]]]) array.splice(index[, howMany[, element1[, …[, elementN]]]])

A

Changes the content of an array, adding new elements while removing old elements.

32
Q

arrayName.unshift(element1, …, elementN)

A

Adds one or more elements to the beginning of an array and returns the new length of the array.

33
Q

Method that applies a function against an accumulator and each value of the array transforming it to a single value.

A

array.reduce(callback[, initialValue])

callback -> function(previousValue, currentValue, index, array){}

34
Q

array.reduce(callback[, initialValue])

callback -> function(previousValue, currentValue, index, array){}

A

Method that applies a function against an accumulator and each value of the array transforming it to a single value.