join, split 應用

gistfile1.js

function getBaseName(str) {
  var segs = str.split('.');
	if(segs.length > 1) segs.pop();
	return segs.join('.');
}

function getExtension(str) {
	var segs = str.split('.');
	if(segs.length <= 1) return '';
	return segs.pop();
}
console.log(getBaseName('my.example.js'));	//my.example
console.log(getExtension('my.example.js'));	//js

var str = 'welcome_to_my_world'.split('_').join('-');
console.log(str);	//welcome-to-my-world
var str = 'welcome_to_my_world'.replace(/_/g, '-');
console.log(str);	//welcome-to-my-world