对json对象进行截取并按照某关键字进行排序

var json = [{"sent_time":"08:29:09","dist":"北京"},{"sent_time":"07:28:55","dist":"上海"},{"sent_time":"08:32:09","dist":"天津"},{"sent_time":"06:29:15","dist":"广州"},{"sent_time":"06:15:24","dist":"深圳"}]

var compare = function (prop) {
return function (obj1, obj2) {
var val1 = obj1[prop];
var val2 = obj2[prop];
if (!isNaN(Number(val1)) && !isNaN(Number(val2))) {
val1 = Number(val1);
val2 = Number(val2);
}
if (val1 < val2) {
return 1;
} else if (val1 > val2) {
return -1;
} else {
return 0;
}
}
}
if(json.length>3){
var data = json.slice(json.length-3,json.slength).sort(compare("age"));
}else {
var data = json.sort(compare("age"));
}
console.log(data);

var s = [{
"draggable": "true",
"name": "58.237.119.223",
"category": "源ip",
"value": "1"
}, {
"draggable": "true",
"name": "254.3.104.223",
"category": "目的ip",
"value": "3"
}, {
"draggable": "true",
"name": "97.19.104.223",
"category": "目的ip",
"value": "2"
}];

s.sort(function(a,b){
return a.value - b.value;
});

s.slice(0,2);