数组排序js

var str=[
    {
    
    name:"a",age:50},
    {
    
    name:"b",age:20},
    {
    
    name:"c",age:40},
    {
    
    name:"d",age:30},
];
function compare(key){
    
    
    return function(value1,value2){
    
    
        var val1=value1[key];
        var val2=value2[key];
        return val1-val2;
    }
}
str.sort(compare('age'));
console.log(str);