JAVASCRIPT

convert camelcase to sentence case javascript

var text = 'helloThereMister';
var result = text.replace( /([A-Z])/g, " $1" );
var finalResult = result.charAt(0).toUpperCase() + result.slice(1);
console.log(finalResult);

camelcase to normal text javascript

"thisStringIsGood"
    // insert a space before all caps
    .replace(/([A-Z])/g, ' $1')
    // uppercase the first character
    .replace(/^./, function(str){ return str.toUpperCase(); })

javascript to camelcase

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());
};