Meaning of javascript text between two slashes

Question

On Dreamweaver if I write on a Javascript document some text between two slashes like

Answer 1

You can use regular expression literals like this:

var pattern = /([0-9]+)/;
if(pattern.test(someString)) {
    // ...
} else {
    // ...
}

See also: https://developer.mozilla.org/en-US/docs/JavaScript/Guide/Regular_Expressions

Answer 2

It's a RegExp literal. I recommend doing your own research on the topic. I could write an introduction to finite automata and regular languages, but you'd always be able to find a better introduction with a little searching.

Answer 3

It is the regular expression literal.

From w3schools:

var patt=new RegExp(pattern,modifiers);

or more simply:

var patt=/pattern/modifiers; 

And from MDN:

RegExp(pattern [, flags])

/pattern/flags