how to check for empty "//" slashes in a input field

Question

I want to check whether a regex field is empty or not and depending on that I want to execute a function. the input field is a regex field and by default it stores "//" value in the field and I dont want to execute a function if the value contains "//". Only when user enters some value I would wnat to execute the function.

new shared.form.RegexField({
                            ref : 'regexField',
                            fieldLabel : 'Regular Expression',
                            allowBlank : false,
                            width : 300,
});

Ex:

var rule = "//";
if(rule) {
// dont do anything;
}

however if rule contains some value like:

rule = "/test/";
if(rule) {
// call API sevrice.
}

is this possible?

Answer 1

if (rule.match("/\/\//")) {
    // don't call because it's equal to "//"
} else {
    // call API service
}

Answer 2

var rule = '//www.example.com'
if(rule.replace(/(\/\/)(?=(\S)*)/,'')){
  //  call API sevrice.
}else {
 // dont do anything;
}