Manipulating substrings with the substr function

Manipulating substrings with the substr function

Sometimes, you want to work with just part of a string that has been assigned. The substr function follows the syntax:

$substring = substr([string you want to extract
from], [beginning point of extraction], [length
of the extracted value]);

For instance, to assign "Sol" to the scalar variable $last_name you would use the following code:

$name = "Selena Sol"; 
$last_name = substr ($name, 7, 3);

The substr function takes the scalar variable $name, and extracts three characters beginning with the seventh.

Warning: as in array indexing, the substr function counts from zero, not from one. Thus, in the string "Gunther", the letter "t" is actually referenced as "3" not "4". Also note that the final number (length of extracted value) is not necessary when you want to grab everything "after" the beginning character. Thus, the following code will do just what the previous did since we are extracting the entire end of the variable $name:

$last_name = substr ($name, 7);

Finding the length of a scalar variable with the length function
Table of Contents
Scalar variable naming conventions

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