JSFiddle - React, Tailwind, and code Playground

JavaScript

//1.)
// replace more than 1 "-" in b
// Expected Output : -asdas-sadf-asdasd-ju

var a = "--asdas-sadf----asdasd---ju";
a = a.replace(/-{2,}/,"");
//alert(a);

//2.)
// remove last "-" and starting "-" from b that is "das-" - after das needs to be removed
// Expected output : welcome/asasdgrd/asd-ast-yret-das/456

var b = "-welcome/asasdgrd/asd-ast-yret-das-/456"
b = b.replace(/[-$]/,"");
//alert(b);