JavaScript Glossary: Array.some()

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Basics

This method checks if any of the elements contained in an array passes a set test. If at least one of the elements passes this test, true is returned. This method only returns a Boolean.

const result = [10,20,30,40,3].some(function(number){
    return number < 10
})

https://scotch.io/embed/gist/e3954f8bd1a7e85f44385388b19ce94b

The some() method:

• Takes a callback function that is called once for each element.
• Runs each element against the set test.
• Returns true if any of the elements pass the test and false if none of them do.

Syntax

const result = array.some(callback(element[, index[, array]])[, thisArg])

2 Parameters

callback (function, required) The function that executes each of the elements of the array. The callback function is required and can take three parameters:

• element: this is the element currently being executed - required.
• index: the index of the current item - optional.
• array: the array that is currently being processed - optional.

thisArg This is an argument passed to be used as the this value in the callback - optional

Returns a Boolean

A boolean value of true or false is returned once the test is passed or failed respectively.

// create a string
const names = ['John', 'Peter', 'Mary'];
const firstName = 'John'

const hasMyName = names.some(name => name === firstName);
//Output: 'John'

Common Uses and Snippets

Verify the content of objects in an array

Used when checking if any elements within an array matches a test.

https://scotch.io/embed/gist/3064ddddef4aaf5ae9dbf0a171157ce9