What is the substr() function in PHP?
There are several functions in PHP that are used to manipulate strings in PHP. One such function is the substr() function.
substr() is a string manipulation function that will return a substring from the string that was passed based on other parameters of the function that was passed.
Syntax
substr($string,$offset,$length)
Parameter
This function requires three parameters.
-
The first parameter is the
stringinput from which the subtring is to be extracted. -
The
offsetparameter is the second parameter. It indicates the position from which the substring is to start. It is an integervvalue.-
If The
offsetis negative, the substring will be formed starting from the end of the string to end at the offset’th position when counting from zero. -
If
offsetis non-negative, the start of the substring will be the beginning of the string to the offset’th position when counting from zero. -
If the
offsetis greater than the length of the input string, the substring to be returned will be empty.
-
-
The
lengthparameter is more or less optional and indicates the length of the substring to be returned after theoffsethas been set.-
If
lengthis negative, that amount of strings will be removed from the inputstring. -
If the
lengthis positive, that length of string will be returned (at most).
-
Code
<?php$j = 'geography';//Last 3 strings are cutoff and the count//starts from the fourth string counting from end 'Y'//output:"a"$junet = substr($j,-4, -3);//this returns the string from the eight position//output:"hy"$ju = substr($j,7);//Last 3 strings are cutoff and the count starts from//the fourth string counting from beginnig 'g'//output:"ra"$jun = substr($j,4,-3);//starts from the end of the string till the 3rd string//output:phy$june = substr($j,-3);//starts the substring from the 6th position//Output: aphy$juneth = substr($j,5,5);echo $junet."\n";echo $ju ."\n";echo $jun ."\n";echo $june."\n";echo $juneth."\n";?>
Explanation
The comments attached to the code provide a very detailed explanation of what the code does. However, to summarize, the substr() function will you get the set of strings that you would wish to get from a string input. All you need to do is provide the string input and the offset length, and you are good to go.
