8. 有关函数的系统函数(记)
![](https://images2017.cnblogs.com/blog/1065651/201712/1065651-20171224214508756-1496423860.jpg)
![](https://images2017.cnblogs.com/blog/1065651/201712/1065651-20171224214508990-1738948103.jpg)
其他的系统函数:
![](https://images2017.cnblogs.com/blog/1065651/201712/1065651-20171224214509162-1277734204.jpg)
常用内部函数:
*字符串函数
*输出与格式化:echo,print_r,var_dump,print,printf
*字符串去除与填充:trim,ltrim,rtrim,str_pad
*字符串连接与分割:implode,join,explode,str_split
*字符串截取:substr,strchr,strrchr
*字符串替换 :str_replace,substr_replace
*字符串长度与位置:strlen,strpos,strrpos
*字符转换:strtolower,strtoupper,lcfirst,ucfirst,ucwords
*特殊字符处理:nl2br,addslashes,htmlspecialchars,htmlspecialchars_decode