Introduction to php string interception substr function

substr(php is very good language,4,5);
The output is is ve;

1, when start>str length, the return is ();

substr(php is very good language,26,5);
substr(php is very good language,4);
The output is (blank)
The output is is v (indicates that both start and langth are 4 )

2, when start is a negative value, start reading from the end of str (*At this time, it starts reading from -1, not from 0),

substr(php is very good language,-4,5);

The output is uage

3. When length is a negative value, length means reading from the end and intercepting the end position of str.

substr(php is very good language,4,-5);

The output is is very good lan

In addition, explode() splits the function string into arrays; strrev() converts the function string into setlocalhost(content location) sets the local environment.content and specifies the scene information constants that need to be set ( LC_ALL – constant for all subordinates LC_COLLATE – sort order LC_CTYPE – character classification and conversion (for example: convert all characters to lowercase or uppercase) LC_MESSAGES – System message format LC_MONETARY – currency/currency format LC_NUMERIC – Numeric format LC_TIME – date and time format ); location, set the country region, for example, chs. strftime() formats local time/date according to locale settings.

That’s it for introducing these, I hope it will be helpful to everyone. To learn PHP tutorials, come to Programmer’s Home.