TypeScript simplest way to check if item exists in array like C# Linq Any ( using any library )

Question

TypeScript simplest way to check if item exists in array like C# Linq Any ( using any library ). Something like

var myArray=[1,2,3,4];

var is_3_Exist=myArray.Any(x=> x==3);

possible duplicate of [Determine whether an array contains a value](http://stackoverflow.com/questions/1181575/determine-whether-an-array-contains-a-value) — Maximillian Laumeister, Aug 17 '15 at 06:22

score 55 · Answer 1 · answered Aug 17 '15 at 06:28

55

Use .some:

myArray.some(x=>x==3);

answered Aug 17 '15 at 06:28

basarat

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1

Sorry, myArray.some(x=>x==3); is not supported in old browser – JavaScript Linq Aug 17 '15 at 06:41
5

Polyfill it : https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/some#Polyfill – basarat Aug 17 '15 at 07:44
https://caniuse.com/mdn-javascript_builtins_array_some – Thomas Mulder Apr 19 '23 at 10:22

seven · Answer 2 · 2018-01-23T15:03:22.300

5

FIDDLE: https://jsfiddle.net/vktawbzg/

NPM: https://www.npmjs.com/package/linqscript

GITHUB: https://github.com/sevensc/linqscript

Take a look at my Github Repository. It would be great if you guys can help to improve it! https://github.com/sevensc/linqscript

Syntax:

list.Any(c => c.Name === ("Apple"))

edited Jan 23 '18 at 15:03

answered Jan 24 '17 at 21:25

seven

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Could you please tell me how to link your linqscript to already existing TS files? And what should I do to call this stuff from my code? – user216652 Apr 21 '17 at 09:16
i made a npm package, get it there: `npm install linqscript` https://www.npmjs.com/package/linqscript You need to import the namespace. See the Readme for more infos. – seven Apr 26 '17 at 19:13
Ok, I saw the package but don't quite understand how to use it from my TS code. Could you please drop a line of details? – user216652 May 05 '17 at 20:03

score 2 · Answer 3 · answered Sep 01 '17 at 15:44

2

You can use the findindex method :

if( myArray.findIndex(x => x === 3) >= 0) {
    // foud myArray element equals to 3
}

answered Sep 01 '17 at 15:44

abahet

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Nypan · Answer 4 · 2018-01-16T07:04:39.237

1

If this is the only thing you need to do you should go for .some (with polyfill) if you however want Linq functionality for other things as well you should take a look at https://github.com/ReactiveX/IxJS.

edited Jan 16 '18 at 07:04

answered Aug 17 '15 at 13:07

Nypan

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Its nuget package is not working. I found TypeScriptLinq working. – JavaScript Linq Aug 18 '15 at 11:29
https://github.com/Reactive-Extensions/IxJS should work, it is a repo maintained by microsoft. – Nypan Aug 18 '15 at 12:05
What is its Nuget link ? – JavaScript Linq Aug 19 '15 at 03:45

score 1 · Answer 5 · answered Jan 23 '22 at 00:04

There is a TypeScript library for LINQ.

It is called ts-generic-collections-linq.

Providing strongly-typed, queryable collections such as:

List
Dictionary

Easy to use.

NPM

https://www.npmjs.com/package/ts-generic-collections-linq

Sample linq query:

let myArray=[1,2,3,4];

let list = new List(myArray);

let is_3_Exist = list.any(x => x==3);

score 0 · Answer 6 · answered Mar 02 '21 at 00:11

For those who want to fiddle more with prototype to get started writing such 'extension methods':

   if (!Array.prototype.Any) {
  Array.prototype.Any = function <T>(condition: predicate<T>): boolean {
    if (this.length === 0)
      return false;
    let result: boolean = false;
    for (let index = 0; index < this.length; index++) {
      const element = this[index];
      if (condition(element)) {
        result = true;
        break;
      }
    }
    return result;
  }
}

The prototype allows you to add functionality to arrays like and call the functionality easy:

let anyEven = [5, 3, 1, 7, 3, 4, 7].Any(x => x % 2== 0); //true

TypeScript simplest way to check if item exists in array like C# Linq Any ( using any library )

6 Answers6