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Abe Layee
Abe Layee
8,378 Points

Please explain " for in" loop to me.

Good day. I am confused with the for in loop. Even though I passed the challenge, I don't feel like I understand it well. I understand the basic of creating an object, but accessing the values with 'for in' is what I don't understand. Can anyone please explain this 'for in' to me. I appreciate it and thank you

var shanghai = {
  population: 14.35e6,
  longitude: '31.2000 N',
  latitude: '121.5000 E',
  country: 'CHN'
for (var key in shanghai) {
  console.log(key, ':' ,shanghai[key]);

1 Answer

18,813 Points

I find it helpful to read it like, [for] each property [in] this object, do something. You could achieve the same effect using a regular for loop, for in is just an easy way to iterate over the properties.

So in this case you're saying [for] each property [in] the shanghai object, print the key and value pair with a : in between.