js 策略模式

定义的一组算法（封装的功能或者模块，具有多种键的json对象被一个统一的方法管理）封装起来，使其相互之间可以替换。

适合表单验证

//策略
var strategy={
 ???jump:function (who) {
 ???????console.log(who+‘ is jump‘);
 ???},
 ???run:function (who) {
 ???????console.log(who+‘ is run‘);
 ???}
};
//统一处理方法
var useStrategy=(function () {
 ???return{
 ???????on:function (arg1, arg2) {
 ???????????strategy[arg1] && strategy[arg1](arg2);
 ???????},
 ???????add:function (param, fn) {
 ???????????if(typeof strategy[param]===‘undefined‘){
 ???????????????strategy[param]=fn;
 ???????????}else{
 ???????????????console.warn(‘这个方法已经存在‘);
 ???????????}
 ???????}
 ???}
})();
useStrategy.on(‘jump‘,‘james‘);
useStrategy.add(‘jump‘,function () {
 ???console.log(‘1‘)
});
useStrategy.add(‘eat‘,function () {
 ???console.log(‘eating‘)
});
useStrategy.on(‘eat‘)