How to change the value of a certain bit in a string in js

In JavaScript, strings are immutable, but the character value at a specified index can be changed in two ways: splitting the string using String.prototype.substr() and String.prototype.concat() and reconnect. Replaces characters at the specified index using a regular expression.

How to change the value of a certain bit of a string in JavaScript

In JavaScript, strings cannot variable, which means we cannot directly change its individual characters. However, there are two ways to change the value of a certain bit in a string:

1. Use String.prototype.substr() and String.prototype.concat()

This method involves splitting the string into two parts: the part before the character you want to change and the remaining part after the character you want to change. Then, insert the new character into the middle section and reconnect all the sections.

<code class="javascript">const str = "Hello World";
const index = 6; // 字符 "o" 的索引
const newChar = "a";

const newStr = str.substr(0, index) + newChar + str.substr(index + 1);</code>

2. Using regular expressions

This method uses regular expressions to replace characters at specific indexes. When creating a regular expression, use ^ (indicates the beginning of the string) and $ (indicates the end of the string) to specify the characters to replace.

<code class="javascript">const str = "Hello World";
const index = 6; // 字符 "o" 的索引
const newChar = "a";

const newStr = str.replace(new RegExp(`^.{{{index}}}`), newChar);</code>

No matter which method is used, the changed string will be stored in a new variable, while the original string will remain unchanged.

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