Javascript遍历JSON数组

Question

我正在尝试遍历如下所示的JSON数组-

var results = [{"city_name":"Bradford","counter":1},{"city_name":"Aberdeen","counter":1},{"city_name":"Aberfeldy","counter":1},{"city_name":"Aberaeron","counter":1},{"city_name":"Aberdare","counter":0},{"city_name":"Abergavenny","counter":0},{"city_name":"Abergele","counter":0}];

for(var i = 0; i  < results.length; i++) {
    var obj = results[i];                   
    console.log(obj.city_name);
    console.log(obj.counter);
}

但我得到的所有信息在警报中均未定义。

Answer 1

它的工作

let results=[{"city_name":"Bradford","counter":1},{"city_name":"Aberdeen","counter":1},{"city_name":"Aberfeldy","counter":1},{"city_name":"Aberaeron","counter":1},{"city_name":"Aberdare","counter":0},{"city_name":"Abergavenny","counter":0},{"city_name":"Abergele","counter":0}]


for(var i = 0; i  < results.length; i++) {
    var obj = results[i];                   
    console.log(obj.city_name);
    console.log(obj.counter);
}
//second way
results.forEach(a=>{
console.log(a.city_name);
    console.log(a.counter);
})

Answer 2

不太了解您，但也许是帮助

const results = [{"city_name":"Bradford","counter":1},{"city_name":"Aberdeen","counter":1},{"city_name":"Aberfeldy","counter":1},{"city_name":"Aberaeron","counter":1},{"city_name":"Aberdare","counter":0},{"city_name":"Abergavenny","counter":0},{"city_name":"Abergele","counter":0}]

for(let i in results) {
    console.log("city_name",results[i].city_name); 
    console.log("counter",results[i].counter);           
}

Answer 3

我尝试了您的代码，它可以工作。但最好这样写：

results.forEach(result => alert(result.city_name));

无论如何，它甚至可以与您的语法一起使用。