TypeScript - replace first n characters in string

In this article, we would like to show you how to replace the first n characters in string in TypeScript.

Quick solution

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const text: string = 'ABCD';

const n: number = 3;

const result: string = 'xyz' + text.slice(n);

​

console.log(result); // xyzD

or:

xxxxxxxxxx

const text: string = 'ABCD';

const n: number = 3;

const replacer: string = 'xyz';

​

const result: string = replacer.concat(text.slice(n));

​

console.log(result); // xyzD

In this example, we use string slice() method to remove the first n characters of the text string. Then with + operator we add the remainder of the text to the replacer.

Runnable example:

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// ONLINE-RUNNER:browser;

​

const text: string = 'ABCD';

const n: number = 3;

const replacer: string = 'xy';

​

const result: string = replacer + text.slice(n);

​

console.log(result); // xyD

Output:

xxxxxxxxxx

xyD

Note:

The replacer for the n removed characters may cosist of any number of characters, not exactly n.

In this example, we use string slice() method to remove the first n characters of the text string. Then with concat() method we add the remainder of the text to the replacer.

Runnable example:

xxxxxxxxxx

const text: string = 'ABCD';

const n: number = 3;

const replacer: string = 'xy';

​

const result: string = replacer.concat(text.slice(n));

​

console.log(result); // xyD

Note:

The replacer for the n removed characters may cosist of any number of characters, not exactly n.

Output:

xxxxxxxxxx

xyD