打印对象的键和值

Question

我想从javascript对象打印一个键:值对.我可以在我的数组中使用不同的键,因此无法将其硬编码到object [0] .key1

var filters = [{"user":"abc"},{"application":"xyz"}];
console.log(Object.keys(filters[0])[0]); // prints user
var term = (Object.keys(filters[0])[0]);
console.log(filters[0].term); // prints undefined

如何打印密钥的值

Answer 1

for (key in filters[0]){
    console.log( key + ": " + filters[0][key]);
}

或者,如果要打印过滤器的所有值

for (i in filters){
    console.log(i);
    for (key in filters[i]){
        console.log( key + ": " + filters[i][key]);
    }
}

关于@mplungjan的评论

filters.forEach(function(obj, index){
    console.log(index);
    for (var key in obj){
        console.log(key, obj[key]);
    }
});

Answer 2

这是寻找一个term属性filters[0]:

console.log(filters[0].term);

你真正想要做的是使用值的term(在你的例子,这将是"user")作为属性标识符:

console.log(filters[0][term]);

Answer 3

for 数组的 for 循环和对象的 for..in 迭代：

var filters = [{ "user": "abc"}, {"application": "xyz"}];

for (var i = 0; i < filters.length; i++) { // the plainest of array loops
  var obj = filters[i];
  // for..in object iteration will set the key for each pair
  // and the value is in obj[key]
  for (var key in obj) { 
    console.log(key, obj[key])
  }
}

ES6

[{ "user": "abc"}, {"application": "xyz"}].forEach(
  obj => console.log(Object.entries(obj).flat())
)