Introduction:

[arrays] are a list of variables. They are stored in square brackets, but can be created using new Array() round brackets.

myArray = ["one", "two", 3, 4, true, "true", false, "false"];

let myNewArray = new Array(1, 2, "three", "four");

1. Declare (create) an array

let x = [];

Empty [array]

let y = ["No", "longer", "empty"];

Filled [array]



2. Create an array from a string
Array.from(string)

Method 1

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string.split(delimiter)

Method 2



3. Transform an array into a string

myArray.toString();

Converts an [array] into a "string"

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myArray.join(separator);

Converts an [array] into a "string"

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4. Retrieving Information

myArray[3];

myNewArray[3];

Get value at position #3

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myArray.indexOf(item, (start));

Get index of [array] value

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myArray.valueOf();

Get values of [array]

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typeof(myArray[#]);

Get data types of values in [array]

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Array.isArray(myArray);

Determines if [array] or not. Returns boolean

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myArray.entries();

Iterate through [array] and return key/value

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myArray.forEach(item, index);

Iterate through [array] and return key/value

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myArray.keys();

Iterate through [array] and return keys

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myArray.constructor;

Returns constructor function for an object, thus tells whether something is a Number, a "string" or an [array]

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myArray.length;

Returns the number of elements in an [array]

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myArray.indexOf(item, (start));

Returns the index of elements in an [array]

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myArray.lastIndexOf(item, (start));

Returns the last index of elements in an [array]

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myArray.includes(item, (start));

Checks if an [array] contains a specific value. Returns a boolean

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