Web Front-end
JS Tutorial
Usage difference analysis of three common ways to intercept strings in javascript
Usage difference analysis of three common ways to intercept strings in javascript
stringObject.substring(start,stop) Used to extract the characters between two specified subscripts in the string.
startRequired. A nonnegative integer that specifies the position in stringObject of the first character of the substring to be extracted.
stop is optional. A nonnegative integer that is one position in the stringObject that is one more than the last character of the substring to be extracted. If this parameter is omitted, the returned substring will go to the end of the string.
start starts from 0 and ends with stop (not including stop). Negative parameters are not accepted.
stringObject.substr(start,length)Can extract the specified number of characters starting from the start subscript in the string
start Required. The starting index of the substring to be extracted. Must be a numeric value. If negative, this parameter declares the position from the end of the string. That is, -1 refers to the last character in the string, -2 refers to the second to last character, and so on.
length Optional. The number of characters in the substring. Must be a numeric value. If this parameter is omitted, the string from the beginning to the end of stringObject is returned.
stringObject.slice(start,end)Extract a certain part of the string and return the extracted part as a new string
start To The starting index of the extracted fragment. If it is a negative number, this parameter specifies the position starting from the end of the string. That is, -1 refers to the last character of the string, -2 refers to the second to last character, and so on.
end The index immediately following the end of the segment to be extracted. If this parameter is not specified, the substring to be extracted includes the string from start to the end of the original string. If this parameter is negative, it specifies the position from the end of the string.
Return the new string including all characters of the string stringObject from start (including start) to end (excluding end)
string.slice() string.substring() string.substr() var stringValue = “hello world”; alert(stringValue.slice(3)); //”lo world” alert(stringValue.substring(3)); //”lo world” alert(stringValue.substr(3)); //”lo world” alert(stringValue.slice(3,7)); //”lo w” alert(stringValue.substring(3,7)); //”lo w” alert(stringValue.substr(3,7)); //”lo worl”
If there is only one parameter among the three n will return the remaining string starting from the nth position (calculating the position starting from 0)
If there are two parameters n, m, slice and substring, it will return from the nth position. The string at the m-th position (not including the m-th position), and substr will return m characters starting from the n-th position.
string.slice() string.substring() string.substr() var stringValue = “hello world”; alert(stringValue.slice(-3)); //”rld” alert(stringValue.substring(-3)); //”hello world” alert(stringValue.substr(-3)); //”rld” alert(stringValue.slice(3,-4)); //”lo w” alert(stringValue.substring(3,-4)); //”hel” alert(stringValue.substr(3,-4)); //”"(空字符串)
When the parameter is a negative value, slice will add the incoming negative value to the string length (string.length), substr will add the negative first parameter to the string length, and the second are converted to 0, substring will convert all negative values to 0.
IE's JavaScript implementation has a problem when handling negative values passed to the substr() method, and it returns the original string.
The above is the detailed content of Usage difference analysis of three common ways to intercept strings in javascript. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
Recommended: Excellent JS open source face detection and recognition project
Apr 03, 2024 am 11:55 AM
Face detection and recognition technology is already a relatively mature and widely used technology. Currently, the most widely used Internet application language is JS. Implementing face detection and recognition on the Web front-end has advantages and disadvantages compared to back-end face recognition. Advantages include reducing network interaction and real-time recognition, which greatly shortens user waiting time and improves user experience; disadvantages include: being limited by model size, the accuracy is also limited. How to use js to implement face detection on the web? In order to implement face recognition on the Web, you need to be familiar with related programming languages and technologies, such as JavaScript, HTML, CSS, WebRTC, etc. At the same time, you also need to master relevant computer vision and artificial intelligence technologies. It is worth noting that due to the design of the Web side
How to determine whether a Golang string ends with a specified character
Mar 12, 2024 pm 04:48 PM
Title: How to determine whether a string ends with a specific character in Golang. In the Go language, sometimes we need to determine whether a string ends with a specific character. This is very common when processing strings. This article will introduce how to use the Go language to implement this function, and provide code examples for your reference. First, let's take a look at how to determine whether a string ends with a specified character in Golang. The characters in a string in Golang can be obtained through indexing, and the length of the string can be
How to intercept a string in Go language
Mar 13, 2024 am 08:33 AM
Go language is a powerful and flexible programming language that provides rich string processing functions, including string interception. In the Go language, we can use slices to intercept strings. Next, we will introduce in detail how to intercept strings in Go language, with specific code examples. 1. Use slicing to intercept a string. In the Go language, you can use slicing expressions to intercept a part of a string. The syntax of slice expression is as follows: slice:=str[start:end]where, s
How to repeat a string in python_python repeating string tutorial
Apr 02, 2024 pm 03:58 PM
1. First open pycharm and enter the pycharm homepage. 2. Then create a new python script, right-click - click new - click pythonfile. 3. Enter a string, code: s="-". 4. Then you need to repeat the symbols in the string 20 times, code: s1=s*20. 5. Enter the print output code, code: print(s1). 6. Finally run the script and you will see our return value at the bottom: - repeated 20 times.
Detailed explanation of the method of converting int type to string in PHP
Mar 26, 2024 am 11:45 AM
Detailed explanation of the method of converting int type to string in PHP In PHP development, we often encounter the need to convert int type to string type. This conversion can be achieved in a variety of ways. This article will introduce several common methods in detail, with specific code examples to help readers better understand. 1. Use PHP’s built-in function strval(). PHP provides a built-in function strval() that can convert variables of different types into string types. When we need to convert int type to string type,
How to solve the problem of Chinese garbled characters when converting hexadecimal to string in PHP
Mar 04, 2024 am 09:36 AM
Methods to solve Chinese garbled characters when converting hexadecimal strings in PHP. In PHP programming, sometimes we encounter situations where we need to convert strings represented by hexadecimal into normal Chinese characters. However, in the process of this conversion, sometimes you will encounter the problem of Chinese garbled characters. This article will provide you with a method to solve the problem of Chinese garbled characters when converting hexadecimal to string in PHP, and give specific code examples. Use the hex2bin() function for hexadecimal conversion. PHP’s built-in hex2bin() function can convert 1
How to check if a string starts with a specific character in Golang?
Mar 12, 2024 pm 09:42 PM
How to check if a string starts with a specific character in Golang? When programming in Golang, you often encounter situations where you need to check whether a string begins with a specific character. To meet this requirement, we can use the functions provided by the strings package in Golang to achieve this. Next, we will introduce in detail how to use Golang to check whether a string starts with a specific character, with specific code examples. In Golang, we can use HasPrefix from the strings package
The relationship between js and vue
Mar 11, 2024 pm 05:21 PM
The relationship between js and vue: 1. JS as the cornerstone of Web development; 2. The rise of Vue.js as a front-end framework; 3. The complementary relationship between JS and Vue; 4. The practical application of JS and Vue.
