ignore case sensitive in javascript code example

Example 1: compare string camelcase and lowercase javascript

str.toUpperCase() === str || str.toLowerCase() === str;

Example 2: js ignore case

var str = "Visit W3Schools!";
var patt1 = /W3S/i;
var res = patt1.ignoreCase

Example 3: compare string camelcase and lowercase javascript

function sameCase(str) {
  return /^[A-Z]+$/.test(str) || /^[a-z]+$/.test(str);
}