Function that returns the number of occurrences of a certain string in the string. This function is the equivalent of the method .count()

To check for a certain string:

var mystring = "The quick brown fox jumps over the lazy dog";
var numberofoccurances = string_count(mystring, "a");

To check case insensitive:

var mystring = "The quick brown fox jumps over the lazy dog";
var search = "a";
var numberofoccurances = string_count(mystring.toLowerCase(), search.toLowerCase());