Iterate in reverse
for (let i = array.length; i >= 0; i--)| Method | Description |
|---|---|
| new Set() | Creates a new Set |
| add() | Adds a new element to the Set |
| delete() | Removes an element from a Set |
| has() | Returns true if a value exists |
| clear() | Removes all elements from a Set |
| forEach() | Invokes a callback for each element |
| values() | Returns an Iterator with all the values in a Set |
| keys() | Same as values() |
| entries() | Returns an Iterator with the [value,value] pairs from a Set |
And here is the property table:
| Property | Description |
|---|---|
| size | Returns the number elements in a Set |
| Method | Description |
|---|---|
| new Map() | Creates a new Map object |
| set() | Sets the value for a key in a Map |
| get() | Gets the value for a key in a Map |
| clear() | Removes all the elements from a Map |
| delete() | Removes a Map element specified by a key |
| has() | Returns true if a key exists in a Map |
| forEach() | Invokes a callback for each key/value pair in a Map |
| entries() | Returns an iterator object with the [key, value] pairs in a Map |
| keys() | Returns an iterator object with the keys in a Map |
| values() | Returns an iterator object of the values in a Map |
| Method | Description |
|---|---|
| push() | Adds one or more elements to the end of an array and returns the new length of the array. |
| pop() | Removes the last element from an array and returns that element. |
| shift() | Removes the first element from an array and returns that element. |
| unshift() | Adds one or more elements to the front of an array and returns the new length of the array. |
| slice() | Returns a shallow copy of a portion of an array into a new array object. |
| splice() | Changes the contents of an array by removing or replacing existing elements and/or adding new elements in place. |
| join() | Joins all elements of an array into a string. |
| reverse() | Reverses the order of the elements in an array. |
| concat() | Merges two or more arrays. |
| forEach() | Executes a provided function once for each array element. |
| map() | Creates a new array populated with the results of calling a provided function on every element in the calling array. |
| filter() | Creates a new array with all elements that pass the test implemented by the provided function. |
| reduce() | Applies a function against an accumulator and each element in the array (from left to right) to reduce it to a single output value. |
| some() | Tests whether at least one element in the array passes the test implemented by the provided function. |
| every() | Tests whether all elements in the array pass the test implemented by the provided function. |
| find() | Returns the value of the first element in the array that satisfies the provided testing function. Otherwise undefined is returned. |
| indexOf() | Returns the first index at which a given element can be found in the array, or -1 if it is not present. |
| findIndex() | Returns the index of the first element in the array that satisfies the provided testing function. Otherwise, it returns -1. |
| includes() | Determines whether an array includes a certain value among its entries. |
| sort() | Sorts the elements of an array in place and returns the array. |
| flat() | Creates a new array with all sub-array elements concatenated into it recursively up to the specified depth. |
| flatMap() | Returns a new array formed by applying a given callback function to each element of the array, and then flattening the result by one level. |
| fill() | Changes all elements in an array to a static value, from a start index (default 0) to an end index (default array.length). |
| Method | Description |
|---|---|
| charAt() | Returns the character at the specified index. |
| concat() | Combines the text of two strings and returns a new string. |
| includes() | Determines whether one string may be found within another string. |
| indexOf() | Returns the index within the calling String object of the first occurrence of the specified value. |
| lastIndexOf() | Returns the index within the calling String object of the last occurrence of the specified value. |
| match() | Used to match a regular expression against a string. |
| replace() | Used to replace a specified value with another value in a string. |
| search() | Executes a search for a match between a regular expression and this String object. |
| slice() | Extracts a section of a string and returns it as a new string. |
| split() | Splits a String object into an array of strings by separating the string into substrings. |
| substr() | Returns the characters in a string beginning at the specified location through the specified number of characters. |
| substring() | Returns the characters in a string between two indexes into the string. |
| toLowerCase() | Returns the calling string value converted to lowercase. |
| toUpperCase() | Returns the calling string value converted to uppercase. |
| trim() | Trims whitespace from the beginning and end of the string. |
| trimStart() | Trims whitespace from the beginning of the string. |
| trimEnd() | Trims whitespace from the end of the string. |
| startsWith() | Determines whether a string begins with the characters of a specified string. |
| endsWith() | Determines whether a string ends with the characters of a specified string. |
| repeat() | Constructs and returns a new string which contains the specified number of copies of the string on which it was called, concatenated together. |
| length | Returns the length of the string. |