CODE EXAMPLE FOR JAVASCRIPT

javascript regex number only

let test = "1(919)-723-9378"
console.log(test.replace(/[^d]/g, "")) // output: 19197239378
/D/g     //D is everything not d
/[^d]/g  //d is numerical characters 0-9
/[^0-9]/g //The ^ inside [] means not, so in this case, not numerical characters