Access the element at the given index.
Access the element at the given index.
concat creates a new array consisting of the elements in the this object on which it is called, followed in order by, for each argument, the elements of that argument (if the argument is an array) or the argument itself (if the argument is not an array).
concat creates a new array consisting of the elements in the this object on which it is called, followed in order by, for each argument, the elements of that argument (if the argument is an array) or the argument itself (if the argument is not an array).
MDN
concat creates a new array consisting of the elements in the this object on which it is called, followed in order by, for each argument, the elements of that argument (if the argument is an array) or the argument itself (if the argument is not an array).
concat creates a new array consisting of the elements in the this object on which it is called, followed in order by, for each argument, the elements of that argument (if the argument is an array) or the argument itself (if the argument is not an array).
MDN
The every method executes the provided callback function once for each element present in the array until it finds one where callback returns a falsy value (a value that becomes false when converted to a Boolean).
The every method executes the provided callback function once for each element present in the array until it finds one where callback returns a falsy value (a value that becomes false when converted to a Boolean). If such an element is found, the every method immediately returns false. Otherwise, if callback returned a true value for all elements, every will return true. callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.
callback is invoked with three arguments:
- the value of the element - the index of the element - and the Array object being traversed.
If a thisObject parameter is provided to every, it will be used as the this for each invocation of the callback. If it is not provided, or is null, the global object associated with callback is used instead.
every does not mutate the array on which it is called.
every acts like the "for all" quantifier in mathematics. In particular, for an empty array, it returns true. (It is vacuously true that all elements of the empty set satisfy any given condition.)
MDN
filter calls a provided callback function once for each element in an array, and constructs a new array of all the values for which callback returns a true value.
filter calls a provided callback function once for each element in an array, and constructs a new array of all the values for which callback returns a true value. callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values. Array elements which do not pass the callback test are simply skipped, and are not included in the new array.
callback is invoked with three arguments:
- the value of the element - the index of the element - the Array object being traversed
If a thisObject parameter is provided to filter, it will be used as the this for each invocation of the callback. If it is not provided, or is null, the global object associated with callback is used instead.
filter does not mutate the array on which it is called.
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forEach executes the provided callback once for each element of the array with an assigned value.
forEach executes the provided callback once for each element of the array with an assigned value. It is not invoked for indexes which have been deleted or which have been initialized to undefined.
callback is invoked with three arguments:
- the element value - the element index - the array being traversed
If a thisArg parameter is provided to forEach, it will be used as the this value for each callback invocation as if callback.call(thisArg, element, index, array) was called. If thisArg is undefined or null, the this value within the function depends on whether the function is in strict mode or not (passed value if in strict mode, global object if in non-strict mode).
MDN
Every object descended from Object inherits the hasOwnProperty method.
Every object descended from Object inherits the hasOwnProperty method. This method can be used to determine whether an object has the specified property as a direct property of that object; unlike the in operator, this method does not check down the object's prototype chain.
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The indexOf() method returns the first index at which a given element can be found in the array, or -1 if it is not present.
The indexOf() method returns the first index at which a given element can be found in the array, or -1 if it is not present.
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The isPrototypeOf mehtod allows you to check whether or not an object exists within another object's prototype chain.
The isPrototypeOf mehtod allows you to check whether or not an object exists within another object's prototype chain.
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The join() method joins all elements of an array into a string.
The join() method joins all elements of an array into a string.
separator Specifies a string to separate each element of the array. The separator is converted to a string if necessary. If omitted, the array elements are separated with a comma.
The lastIndexOf() method returns the last index at which a given element can be found in the array, or -1 if it is not present.
The lastIndexOf() method 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.
MDN
Length of the array.
Length of the array.
map calls a provided callback function once for each element in an array, in order, and constructs a new array from the results.
map calls a provided callback function once for each element in an array, in order, and constructs a new array from the results. callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.
callback is invoked with three arguments: the value of the element, the index of the element, and the Array object being traversed.
If a thisArg parameter is provided to map, it will be used as the this for each invocation of the callback. If it is not provided, or is null, the global object associated with callback is used instead.
map does not mutate the array on which it is called.
MDN
The pop() method removes the last element from an array and returns that element.
The pop() method removes the last element from an array and returns that element.
MDN
Every object has a propertyIsEnumerable method.
Every object has a propertyIsEnumerable method. This method can determine whether the specified property in an object can be enumerated by a for...in loop, with the exception of properties inherited through the prototype chain. If the object does not have the specified property, this method returns false.
MDN
The push() method mutates an array by appending the given elements and returning the new length of the array.
The push() method mutates an array by appending the given elements and returning the new length of the array.
MDN
reduce executes the callback function once for each element present in the array, excluding holes in the array, receiving four arguments: the initial value (or value from the previous callback call), the value of the current element, the current index, and the array over which iteration is occurring.
reduce executes the callback function once for each element present in the array, excluding holes in the array, receiving four arguments: the initial value (or value from the previous callback call), the value of the current element, the current index, and the array over which iteration is occurring.
The first time the callback is called, previousValue and currentValue can be one of two values. If initialValue is provided in the call to reduce, then previousValue will be equal to initialValue and currentValue will be equal to the first value in the array. If no initialValue was provided, then previousValue will be equal to the first value in the array and currentValue will be equal to the second.
MDN
reduceRight executes the callback function once for each element present in the array, excluding holes in the array, receiving four arguments: the initial value (or value from the previous callback call), the value of the current element, the current index, and the array over which iteration is occurring.
reduceRight executes the callback function once for each element present in the array, excluding holes in the array, receiving four arguments: the initial value (or value from the previous callback call), the value of the current element, the current index, and the array over which iteration is occurring.
MDN
The reverse() method reverses an array in place.
The reverse() method reverses an array in place. The first array element becomes the last and the last becomes the first.
MDN
The shift() method removes the first element from an array and returns that element.
The shift() method removes the first element from an array and returns that element. This method changes the length of the array.
MDN
The slice() method returns a shallow copy of a portion of an array.
The slice() method returns a shallow copy of a portion of an array.
MDN
some executes the callback function once for each element present in the array until it finds one where callback returns a true value.
some executes the callback function once for each element present in the array until it finds one where callback returns a true value. If such an element is found, some immediately returns true. Otherwise, some returns false. callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.
callback is invoked with three arguments: the value of the element, the index of the element, and the Array object being traversed.
If a thisObject parameter is provided to some, it will be used as the this for each invocation of the callback. If it is not provided, or is null, the global object associated with callback is used instead.
some does not mutate the array on which it is called.
MDN
The sort() method sorts the elements of an array in place and returns the array.
The sort() method sorts the elements of an array in place and returns the array. The sort is not necessarily stable. The default sort order is lexicographic (not numeric).
If compareFunction is not supplied, elements are sorted by converting them to strings and comparing strings in lexicographic ("dictionary" or "telephone book," not numerical) order. For example, "80" comes before "9" in lexicographic order, but in a numeric sort 9 comes before 80.
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The splice() method changes the content of an array, adding new elements while removing old elements.
The splice() method changes the content of an array, adding new elements while removing old elements.
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The splice() method changes the content of an array, adding new elements while removing old elements.
The splice() method changes the content of an array, adding new elements while removing old elements.
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The unshift() method adds one or more elements to the beginning of an array and returns the new length of the array.
The unshift() method adds one or more elements to the beginning of an array and returns the new length of the array.
MDN
Set the element at the given index.
Set the element at the given index.