strspn Find length of initial segment matching mask intstrspn stringstr1 stringstr2 intstart intlength Returns the length of the initial segment of str1 which consists entirely of characters in str2. The line of code: ]]> will assign 2 to $var, because the string "42" will be the longest segment containing characters from "1234567890". As of PHP 4.3.0, strspn accepts two optional integer parameters that can be used to define the start position and the length of the string to examine. ]]> ¬e.bin-safe; See also strcspn.