$substr¶
Description:
Returns the substring of text
beginning with the character at the start
index, up to (but not including) the character at the end
index. Indexes are
zero-based. Negative numbers will be counted back from the end of the string. If
the start or end indexes are left blank, they will default to the start and end
of the string respectively. If the start
index evaluates to a negative
number (e.g.: text
is “abc” and start
is -10), it will default to the
start of the string. Similarly, if end
index is a number greater than the
number of characters in the string, it will default to the end of the string.
Invalid index values (e.g.: start
greater than end
) will return an empty
string.
Example:
The following statements will return the values indicated:
$substr(abcdefg) ==> "abcdefg"
$substr(abcdefg,3) ==> "defg"
$substr(abcdefg,,3) ==> "abc"
$substr(abcdefg,0,3) ==> "abc"
$substr(abcdefg,-3) ==> "efg"
$substr(abcdefg,-6,3) ==> "bc"
$substr(abcdefg,-10,3) ==> "abc"
$substr(abcdefg,3,1) ==> ""