CODEWITHSUNDEEP
javascriptarraystypescript
Ruman Khan Pathan
Ruman Khan Pathan

Reputation: 137

How to create arrays and assign value to any index in typescript

How can i achieve following javascript code in typescript.

var childs = [];
childs[34] = [12,23,54,65];
childs[122] = [43,56,23,31];
childs[212343] = [345,643,24,745];
console.log(childs);

Upvotes: 2

Views: 10281

Answers (1)

Nitzan Tomer
Nitzan Tomer

Reputation: 164139

Your code is already a valid typescript code as typescript is a superset of javascript.

However, typescript lets you have types, so in this case you can do this:

var childs: number[][] = [];
childs[34] = [12,23,54,65];
childs[122] = [43,56,23,31];
childs[212343] = [345,643,24,745];
console.log(childs);

(code in playground)

Notice that the only thing I added was the type of childs (number[][]), which can also be written like:

var childs: Array<number[]> = [];
// or
var childs: Array<Array<number>> = [];

You'll get a compiler error if you try to add anything else to the array:

childs.push(4); // error: Argument of type '4' is not assignable to parameter of type 'number[]'
childs.push([2, "4"]); // error: Argument of type '(string | number)[]' is not assignable to parameter of type 'number[]'

Upvotes: 1

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