php笔记之：php函数range() round()和list()的使用说明
一>>
range()函数快速创建数组的简单方法,使用low到high范围的整数值填充数组,函数将返回一个包含次范围内所有整数的数组.形式如下
array range(int low,int high[,int step])
典型用法如下
例子:建立1-6的6个数字的数组(骰子)
$die = range(0,6);
建立0-30所有双数的数组
$even = (0,20,2);//步长为2
这个函数不仅仅可以用作数字,还可以用作字母.
如
$words = range('A','Z');
将建立包含A到Z的的所有字母的数组.此处可以用于生成验证码函数.
二>>
round()函数
这个函数是怕我记混淆了.这个函数和上面的哪个range()是天壤之别.
这个函数的作用是
取浮点数的精度
float round(float var[,int preisin})
典型用法
例: $pi = 3.141592653;
round($pi,4);
echo $pi;
将输出 3.1415
三>>
list()函数
list()函数可以在一次操作中从一个数组内提取多个值.同时为变量赋值.形式如下
void list(mixed)
典型用法
<p class="codetitle"><span style="CURSOR: pointer" onclick="doCopy('code98313')"><u>复制代码</u></span> 代码如下:</p>
<p class="codebody" id="code98313"><br><?php <br><br>$info = array('coffee', 'brown', 'caffeine'); <br><br>// Listing all the variables <br>list($drink, $color, $power) = $info; <br>echo "$drink is $color and $power makes it special.\n"; <br><br>// Listing some of them <br>list($drink, , $power) = $info; <br>echo "$drink has $power.\n"; <br><br>// Or let's skip to only the third one <br>list( , , $power) = $info; <br>echo "I need $power!\n"; <br><br>?> <br></p>
<br> |
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
EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function
SublimeText3 Chinese version
Chinese version, very easy to use
Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.
SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
