nodejs string method

In Node.js, there are many string-related methods that can help us process strings easily. This article will introduce some common string methods in Node.js to help you better understand and use strings.

1. indexOf()

indexOf() method can return the position of the first occurrence of the specified string in another string. If the specified string does not appear in another string, -1 is returned. Example:

const str = 'hello world';
const index = str.indexOf('world');
console.log(index); // 输出 6

2. slice()

The slice() method can extract the specified part from a string and return a new string. It takes two parameters: starting position and ending position. If the end position is omitted, it defaults to the end of the string. Example:

const str = 'hello world';
const newStr = str.slice(6);
console.log(newStr); // 输出 world

3. split()

The split() method can split a string into an array. It takes one parameter, the delimiter for splitting. If no delimiter is specified, the entire string is placed into the array as one element. Example:

const str = 'hello,world';
const arr = str.split(',');
console.log(arr); // 输出 ['hello', 'world']

4. replace()

replace() method can replace the specified part of a string with a new string. It takes two parameters: the string to be replaced and the string to replace. Example:

const str = 'hello world';
const newStr = str.replace('world', 'Node.js');
console.log(newStr); // 输出 hello Node.js

5. trim()

Thetrim() method can remove spaces at both ends of a string. Example:

const str = '  hello world  ';
const newStr = str.trim();
console.log(newStr); // 输出 hello world

6. toUpperCase() and toLowerCase()

The toUpperCase() method can convert all letters in a string to uppercase, while toLowerCase() method converts all letters to lowercase. Example:

const str = 'Hello World';
const upperStr = str.toUpperCase();
const lowerStr = str.toLowerCase();
console.log(upperStr); // 输出 HELLO WORLD
console.log(lowerStr); // 输出 hello world

7. charCodeAt() and fromCharCode()

charCodeAt() method can return the Unicode encoding of the character at the specified position in a string, while fromCharCode() Method can create a character based on a Unicode encoding value. Example:

const str = 'hello';
const code = str.charCodeAt(0);
const char = String.fromCharCode(code);
console.log(code); // 输出 104
console.log(char); // 输出 h

Summary

Node.js provides many string-related methods that can help us better handle strings. In actual development, the reasonable use of these methods can greatly improve the efficiency of string processing and reduce the probability of errors. It is one of the important skills in Node.js development.

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