how to get the value of the only key-value pair in object [duplicate]

问题

This question already has answers here:

best way to get the key of a key/value javascript object (16 answers)

Closed 5 years ago.

I have a javascript object like below, a has only one key-value pair, how could I get the value of a1 without using iteration and also without knowing the key name(i.e a1) ?

a: {
            a1:"hello"
        }

回答1:

Since you said you know there's only one key–value pair in the object:

var a = { a1: 'hello' };
Object.keys(a)[0];
var key = Object.keys(a)[0];
a[key]; // yields "hello"

回答2:

You have to loop through i belive.

var t = { 
         a: {
              a1:"hello"
            }
        }

for (u in t) {
    console.log(u); //Outputs "a"
    for (v in t[u]) {
        console.log(v + " " +t[u][v]); //Ouputs "ai hello"
    } 
}

来源：https://stackoverflow.com/questions/24927783/how-to-get-the-value-of-the-only-key-value-pair-in-object