var text = 'helloThereMister';
var result = text.replace( /([A-Z])/g, " $1" );
var finalResult = result.charAt(0).toUpperCase() + result.slice(1);
console.log(finalResult);"thisStringIsGood"
// insert a space before all caps
.replace(/([A-Z])/g, ' $1')
// uppercase the first character
.replace(/^./, function(str){ return str.toUpperCase(); })
String.prototype.toCamelCase = function () {
let STR = this.toLowerCase()
.trim()
.split(/[ -_]/g)
.map(word => word.replace(word[0], word[0].toString().toUpperCase()))
.join('');
return STR.replace(STR[0], STR[0].toLowerCase());
};