How to change the size and length of a certain bit of a string in js

Question: How to change the value or length of a certain bit of a string in JavaScript? Change the value of a certain bit: use charAt() to get the character, and then use replace() to replace it. Change the length: intercept (slice), append (concat) or remove (slice/replace) the string.

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

Change the string The value of a certain bit

Use the charAt() method to get the character at the specified position in the string, and then use the replace() method to replace the character. For example:

<code>const str = "Hello";
const newStr = str.replace("l", "L");
console.log(newStr); // 输出 "HeLLo"</code>

Change the string length

To change the string length, you can use the following method:

• Intercept characters String: Use the slice() method to intercept a part of the string.
• Append strings: Use the concat() method to append one or more strings to an existing string.
• Remove characters: Use the slice() or replace() method to remove characters from the string.

Example:

• Intercept string:

<code>const str = "Hello World";
const newStr = str.slice(0, 5);
console.log(newStr); // 输出 "Hello"</code>

• Append string:

<code>const str = "Hello";
const newStr = str.concat(" World");
console.log(newStr); // 输出 "Hello World"</code>

• Remove characters:

<code>const str = "Hello World";
const newStr = str.replace("World", "");
console.log(newStr); // 输出 "Hello"</code>

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