Enumeration
最后更新于：2022-04-01 03:12:58
# Enumeration
The `for in` statement can loop over all of the property names in an object. The enumeration will include functions and prototype properties.
~~~
var fruit = {
apple: 2,
orange:5,
pear:1
},
sentence = 'I have ',
quantity;
for (kind in fruit){
quantity = fruit[kind];
sentence += quantity+' '+kind+
(quantity===1?'':'s')+
', ';
}
// The following line removes the trailing coma.
sentence = sentence.substr(0,sentence.length-2)+'.';
// I have 2 apples, 5 oranges, 1 pear.
~~~