Introduction to substr function in PHP_PHP tutorial

substr();
substr(str,start,length);
Example: substr(php is very good language,4,5);
The output is is ve;

When start> ;The length of str is returned as ();
substr(php is very good language,26,5);
substr(php is very good language,4);
The output is (blank)
The output is is v (indicating that both start and langth are 4)

When start is a negative value, it starts reading from the end of str (*At this time, it starts reading from -1, not from 0 start),
substr(php is very good language,-4,5);
The output is uage

When length is a negative value, length means reading from the end, intercepting str end position.
substr(php is very good language,4,-5);
The output is is very good lan
explode() splits the function string into an array;
strrev() splits the function string
setlocalhost(content location) sets the local environment.content, and specifies the scene information constants that need to be set (
LC_ALL - constants for all subordinates
LC_COLLATE - sorting order
LC_CTYPE - character classification and conversion (such as : Convert all characters to lowercase or uppercase)
LC_MESSAGES - system information format
LC_MONETARY - currency/currency format
LC_NUMERIC - numerical format
LC_TIME - date and time format
); location, set the country region, for example, chs.
strftime() formats the local time/date according to the regional settings.

http://www.bkjia.com/PHPjc/486083.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/486083.htmlTechArticlesubstr(); substr(str,start,length); Example: substr(php is very good language,4 ,5); The output is is ve; When the length of startstr is, the return is (); substr(php is very good language,26,5)...