第四节 PHP常用功能

第四节 PHP常用功能

1.字符串

<?php
$str = 'Hello Php';

//获取字符所在的位置
echo strpos($str,'o');  //4
echo strpos($str,'Ph'); //6

//截取字符串
$str1= substr($str,2);
echo $str1;    //lo Php
echo '<br>';
//分割
$result =  str_split($str,2);
print_r($result);
echo '<br>';
//字符串分割
$str =  "Hello PHP Java C# C++";
$result =  explode(' ',$str);
print_r($result);
//字符串连接
$str2 = $str.'<br>';
$str2 = "$str<br>Object-c ";
?>

2 数组

<?php
$arr =  array();
$arr[0] = "Hello";
$arr[1] =  "Word";
$arr[2] =  2;
$arr[3] =  3.14;
$arr['h'] = "Hello";
$arr['w'] =  "Word";
$arr =  array('h'=>'Hello', 'w'=>'Word', 'name'=>'Like');
$arr =  array(0=>'Hello', 1=>'Word',2=>'Like');
print_r($arr);

for($i=0;$i<100;$i++)
{
    array_push($arr,'Item'.$i);
}
print_r($arr);

?>

3 include与require

//依赖   每一次引用都会执行
require 'lib.php'// 只执行一次
require_once 'lib.php'//包含
include  'lib.php';