Table of Contents
PHP之sprintf函数用法详解,sprintf函数详解
Home php教程 php手册 PHP之sprintf函数用法详解,sprintf函数详解

PHP之sprintf函数用法详解,sprintf函数详解

Jun 13, 2016 am 09:21 AM
php

PHP之sprintf函数用法详解,sprintf函数详解

本文实例讲述了PHP中sprintf函数的用法。分享给大家供大家参考。具体用法分析如下:

sprintf()函数在php官方是说把字符串格式化输出了,本文就来给各位朋友介绍一下在学习sprintf()函数时的一些经验分享,希望能给大家带来帮助.

PHP函数 sprintf() 函数官方定义为:sprintf():把格式化的字符串写入一个变量中

语法为:sprintf(format,arg1,arg2,arg++);

参数:

format:必须,转换格式

arg1 :必须,规定插入 format 字符串中第一个%符号处的参数

arg1 :可选,规定插入 format 字符串中第二个%符号处的参数

arg1++:可选,规定插入 format 字符串中第三、四等%符号处的参数

参数 format 的转换格式,以百分比符号(%)开始到转换字符结束,下面是有可能的format值.

%% – 返回百分比符号

%b – 二进制数

%c – 依照 ASCII 值的字符

%d – 带符号十进制数

%e – 可续计数法(比如 1.5e+3)

%u – 无符号十进制数

%f – 浮点数(local settings aware)

%F – 浮点数(not local settings aware)

%o – 八进制数

%s – 字符串

%x – 十六进制数(小写字母)

%X – 十六进制数(大写字母)

下面是一些demo,代码如下:

复制代码 代码如下:

// 1. %% :把 %% 替换成 % 
$str = '测试一下 %% 这个参数,会被替换成什么'; 
echo sprintf($str); 
//返回结果: 测试一下 % 这个参数,会被替换成什么(%%被替换成一个%) 

// 2. %b :该参数只能替换整型数据,如果是浮点型,只会取整数部分,会忽略小数点后面的数据。如果是非整型数据。返回 0 
$str = '参数 %b 会替换成二进制数'; 
$arg = '10'; 
echo sprintf($str,$arg); 
//返回结果:参数 1010 会替换成二进制数 
$arg = 10.23; 
echo sprintf($str,$arg); 
//返回结果:参数 1010 会替换成二进制数 
$arg = 'abc'; 
echo sprintf($str,$arg); 
//返回结果:参数 0 会替换成二进制数 

// 3. %c 返回字符编码的ASCII码 
$arg = 65; 
$str =  "数字 {$arg} 对应的ASCII码为 %c "; 
echo sprintf($str,$arg); 
//返回结果:数字 65 对应的ASCII码为 A 
 
// 4. %d 将一段字符里的%d替换成int型,数据要求同 $b 相同 
$str = 'ID号为 %d '; 
$arg = -3; 
echo sprintf($str,$arg); 
//返回结果:ID号为 -3 
$arg = 4.5; 
echo sprintf($str,$arg); 
//返回结果:ID号为 4 
$arg = 'abc'; 
echo sprintf($str,$arg); 
//返回结果:ID号为 0 
 
// 5. %s - 字符串 
$str = "这是用来测试的sprintf的字符串( %s )。今天消费了%f元。从钟楼到小寨有%d站。上班"; 
$arg = '%s'; 
echo sprintf($str,$arg,6,5); 
//返回结果:这是用来测试的sprintf的字符串( %s )。今天消费了6.000000元。从钟楼到小寨有5站。上班


至于其它的参数,大家可以试着测试一下.

下面说一下这个函数的一些用途,比如我们在对一张数据表所有数据做多个字段更新时,如果使用循环更新的话,那是很耗费资源的,这里就要用到我们sprintf()函数了.

在数据库批量更新时,我一般采用 case then when end 的语法来做,基本语法如:

复制代码 代码如下:

UPDATA table 
    SET field = CASE id 
        WHEN 1 THEN 'value1' 
        WHEN 2 THEN 'value2' 
        WHEN 3 THEN 'value3' 
    END 
WHERE id IN (1,2,3)


上面的意思就是说,更新 table 设置 id = 1 的值为 value1, id = 2 的值为 value2 ,id = 3 的值为 value3,这样参数上面的函数将sql语句结合成这样SQL语句,只需一条SQL就可以进行批量更新,具体的方法为:

复制代码 代码如下:

//比如 id 对应的值为以下数组 
$info = array(1=>'张三',2=>'李四',3=>'王五'); 
$ids = implode(',',array_keys($info)) //获取所有的ID字符串 
//组合SQL 
$sql = "UPDATA user SET username = CASE id"; 
foreach($info as $id=>$username){ 
     $sql .= sprintf("WHEN %d THEN %s",$id,$username); 

$sql .= "END WHERE id IN ($ids)"; 
// $model->query($sql)

上面就可以完成批量更新的操作,后面的 where子句确保只有3行数据执行.

希望本文所述对大家的PHP程序设计有所帮助。

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian Dec 24, 2024 pm 04:42 PM

PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati

7 PHP Functions I Regret I Didn't Know Before 7 PHP Functions I Regret I Didn't Know Before Nov 13, 2024 am 09:42 AM

If you are an experienced PHP developer, you might have the feeling that you’ve been there and done that already.You have developed a significant number of applications, debugged millions of lines of code, and tweaked a bunch of scripts to achieve op

How To Set Up Visual Studio Code (VS Code) for PHP Development How To Set Up Visual Studio Code (VS Code) for PHP Development Dec 20, 2024 am 11:31 AM

Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c

Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Apr 05, 2025 am 12:04 AM

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

PHP Program to Count Vowels in a String PHP Program to Count Vowels in a String Feb 07, 2025 pm 12:12 PM

A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total

How do you parse and process HTML/XML in PHP? How do you parse and process HTML/XML in PHP? Feb 07, 2025 am 11:57 AM

This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an

Explain late static binding in PHP (static::). Explain late static binding in PHP (static::). Apr 03, 2025 am 12:04 AM

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases? What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases? Apr 03, 2025 am 12:03 AM

What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.

See all articles