ES6中数组方法（ find )

        var arr = [
            {name:‘jerry‘,sex:‘man‘},
            {name:‘jack‘,sex:‘woman‘},
            {name:‘jack‘,sex:‘man‘}
        ]
        var jack = arr.find(function(obj){
            return obj.name == ‘jack‘;
        })
        console.log(jack);  // 返回符合条件的第一个对象{name: "jack", sex: "woman"}

        var bill = arr.find(function(obj){
            return obj.name == ‘bill‘;
        })
        console.log(bill);  // undefined