JavaScript - replace first 3 characters in string
In this article, we would like to show you how to replace the first 3 characters in string in JavaScript.
Quick solution
xxxxxxxxxxlet text = 'ABCD';let result = 'xyz' + text.slice(3);console.log(result); // xyzDor:
xxxxxxxxxxlet text = 'ABCD';let replacer = 'xyz';let result = replacer.concat(text.slice(3));console.log(result); // xyzDor:
xxxxxxxxxxlet text = 'ABCD';let result = text.replace(/^.{3}/g, 'xyz');console.log(result); // xyzD
In this example, we use string slice() method to remove the first 3 characters of the text string. Then with + operator we add the remainder of the text to the replacer.
Runnable example:
xxxxxxxxxxlet text = 'ABCD';let replacer = 'xy';let result = replacer + text.slice(3);console.log(result); // xyDNote:
The
replacerfor the three removed characters may cosist of any number of characters, not exactly 3.
In this example, we use string slice() method to remove the first 3 characters of the text string. Then with concat() method we add the remainder of the text to the replacer.
Runnable example:
xxxxxxxxxxlet text = 'ABCD';let replacer = 'xy';let result = replacer.concat(text.slice(3));console.log(result); // xyDNote:
The
replacerfor the two removed characters may cosist of any number of characters, not exactly 3.
In this example, we use string replace() with /^.{3}/g regex to replace the first 3 characters in the text string.
Regex explanation:
^- matches the beginning of the string,.- matches any character except linebreaks,{3}- matches the specified quantity of the previous token (in our case the.).
Runnable example:
xxxxxxxxxxlet text = 'ABCD';let result = text.replace(/^.{3}/g, 'xyz');console.log(result); // xyzD