Common functions in PHP

1. Random Number and time

1	echorand();      //随机数生成器

1	echorand(0,10);      //某个范围之间的随机数：第一个参数最小，第二个参数最大；例子是从0-10之间的随机数

1	echotime();      //当前的时间戳

1	echodate("Y",time());         //第一个参数是年份，不写第二个参数也是取得当前时间

1	echodate("Y-m-d H:i:s",1381248000);      //格式化显示时间:Y是指年m是指月份d代表天数H是小时i是分钟s秒数,时间戳

Sometimes time may not be Chinese time, can be modified by two ways:

Method One:

1	date_default_timezone_set("PRC");

Method Two: Modify the date.timezone=ect/gmt-8 in PHP config file php.ini

1	echostrtotime("2013-10-09");      //反向转化: 将字符串转换为时间戳    2013-10-09返回的时间戳是1381248000

2. String functions

12	$str="hello world";echostrlen($str);    //字符串长度: 字符串

String $str= the length of "Hello World" is 11

12	$str="hello world";var_dump(strcmp($str,"hello world"));     //比较两个字符串：字符串，比较的字符串

The return value is 0; (The return value of both equals is 0;str1 less than str2 when the return value is <0,str1 greater than STR2)

12	$str="Hello world";echostrtolower($str);     //将字符串转换为小写

The return is to convert "H" to "H".

12	$str="hello world";echostrtoupper($str);      //将字符串转为大写

The return value is the conversion of "Hello World" to Hello World

12	$str="hello|world|ni|hao";var_dump(explode("|",$str));      //拆分字符串，拆完后返回数组

Results

12	$attr=array("aa","bb","cc","dd");echoimplode("&",$attr);      //将数组拼接一个字符串：想要拼接的符号，拼接的字符串

12	$str="hello|world|ni|hao";echosubstr_replace($str,"***",0,5);      //替换指定位置的字符串    $str,"***",0,5：字符串，替换后的符号，从几开始替换，长度

The return string is replaced with a character that starts at 0 and is 5 characters long.

　　

12	$str="hello|world|ni|hao";echostr_replace("|","***",$str);     //字符串查找替换     "|","***",$str：查找的字符，替换成的字符，字符串

To return is to replace all of the |

12	$str="hello|world|ni|hao";echosubstr($str,0,5);       //截取字符串    $str,0,5：字符串,截取位置，长度

The string that defines the string that starts at 0, which is the length of 5, is the Hello

3. Regular expressions

12	$str= "2hello 5li 6lei";echopreg_replace("/\d/","#",$str);   //替换   "/\d/","#",$str： 正则表达式\d 数字，替换为#,字符串

The return value is the number in the string that is replaced by #

12	$str  =  "2hello 5li 6lei " var_dump (preg_split ( $str //split    regular expression, string

123	$str= "2hello 5li 6lei";preg_match_all("/\d/",$str,$arr);    //正则表达式，定义的字符串，数组var_dump($arr);       //匹配满足所有正则的字符串

The value returned is the number 2,5,6

123	$str= "2hello 5li 6lei";preg_match("/\d/",$str,$arr); var_dump($arr);     //匹配第一个满足正则的字符串

4. Array functions

12	$attr= array(1,2,3,4,5,1);var_dump(in_array(4,$attr));    //判断某个值是否在数组中   索引号，数组

The return value is ture, and if the array is exceeded, the return value is False

12	$attr= array(1,2,3,4,5,1);var_dump(array_reverse($attr));     //翻转数组

The data in the original array is reversed

12	$attr= array(1,2,3,4,5,1);echocount($attr);     //取数组长度

The return value is the length of the array 6

12	$attr= array(1,2,3,4,5,1);var_dump(array_unique($attr));     //去重

The return value is the same as in the array.

123	$attr= array(1,2,3,4,5,1);unset($attr[1]);      //索引号为1的元素var_dump($attr);    //删除数组元素

Deleted the number of index number 1, that is, 2 deleted

12	$attr= array(1,2,3,4,5,1);var_dump(array_values($attr));     //重新索引   打乱的索引重新排过

After re-indexing

12	$attr= array(1,2,3,4,5,1);var_dump(array_merge($attr,array(5,6)));     //合并数组   数组，想要合并的数组

123	$attr= array(1,2,3,4,5,1);array_push($attr,"hello");   //数组，添加的元素var_dump($attr);     //向数组中添加一个元素，返回索引

Example:

12345678910111213

$attr = array(    array("n001","汉族"),    array("n002","回族"),    array("n003","维吾尔族")    ); echo"<select>"; foreach($attras$v){    echo"<option>{$v[1]}</option>";}    echo"</select>";

　

Common functions in PHP