数组过滤总结

var arr = [
    {appid: '7e2702c3', status: 0},
    {appid: 'ad02cfe0', status: 1},
    {appid: '5a64af02', status: 2}
];

var newArr = arr
    .filter(item => item.status === 2)
    .map(item => item.appid);

console.log(newArr);//[ '5a64af02' ]

var arr = [ 
    {'appid':'7e2702c3','status':0},
    {'appid':'ad02cfe0','status':1},
    {'appid':'5a64af02','status':2}
];
arr.find(i => i.status == 2).appid;

var arr = [ 
    {'appid':'7e2702c3','status':0},
    {'appid':'ad02cfe0','status':1},
    {'appid':'5a64af02','status':2}
];
arr.reduce((res,term) => term.status == 2 ? res.concat(term) : res,[])

var arr = [ 
        {'appid':'7e2702c3','status':0},
        {'appid':'ad02cfe0','status':1},
        {'appid':'5a64af02','status':2}
    ],
    newArr = [];

arr.map(function(n) {
    if(n.status === 2) {
        newArr.push(n.appid);
    }
})
console.log(newArr);