四.格式化字符串函数 number_format()

<span>$str</span> = <span>"123445677"</span>;
<span>$strl</span> = number_format(<span>$str</span>);
<span>$str2</span> = number_format(<span>$str</span>,<span>2</span>);
<span>$str3</span> = number_format(<span>$str</span>,<span>2</span>,<span>","</span>,<span>'.'</span>);
<span>echo</span><span>$str</span>.<span>"<br/>"</span>;
<span>echo</span><span>$strl</span>.<span>"<br/>"</span>;
<span>echo</span><span>$str2</span>.<span>"<br/>"</span>;
<span>echo</span><span>$str3</span>.<span>"<br/>"</span>;

 结果如下所示，number_format(str)表示在千分位上加，隔开。number_format(str,2)表示留两位小数点。number_format($str,2,",",".")把“，”替换成“.”。

五.把字符串分割成数组函数/emplode()。把数组连接成字符串函数implode()。

<span>$str</span> = <span>"你好@php编程@每天进步一点"</span>;
<span>$tem</span> = explode(<span>'@'</span>,<span>$str</span>);
<span>$teml</span> = explode(<span>'@'</span>,<span>$str</span>,<span>2</span>);
print_r(<span>$tem</span>);
<span>echo</span><span>"<br/>"</span>;
print_r(<span>$teml</span>);

结果如图:explode(ch,str,limit)。ch表示分割字符串的分割符。str表示字符串。limit可选，表示要分割几次，默认为全部。

<span>$array</span> = <span>array</span>(<span>"hello"</span>,<span>"php编程"</span>,<span>"每天进步一点"</span>);
<span>$str</span> = implode(<span>","</span>,<span>$array</span>);
print_r(<span>$str</span>);

   结果如下图 。implode(separator,array)。 separator表示已什么来合成字符串。可选的。默认为空。array表示要合并成字符串的数组

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六.截取字符串 /substr(str,separator)

<span>$str</span> = <span>"hello,php编程"</span>;
<span>$strm</span> = substr(<span>$str</span>,<span>3</span>);
<span>$strl</span> = substr(<span>$str</span>,-<span>3</span>);
<span>echo</span><span>$strm</span>.<span>"<br/>"</span>;
<span>echo</span><span>$strl</span>;

  substr(str,separator)。str指的是所要截取的字符串。separtor表示从哪里开始截取。正数代表从左开始截取。负数代表从右开始截取。这里3个字符代表一个汉字。（utf-8里是三个字符一个汉字，gb2312里是二个字符一个汉字。）

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以上就介绍了php字符串函数（2），包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。