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JavaScript

Posted by Jackie Jen
Jackie Jen
2,723 Points

how to auto increment property name through looping method

let siad i have objectName[propertyName] as below

{"visited1":"106","visited2":"107","visited3":"104"}

how to use looping to access the property name. Below is my code which cannot access the property name by using looping. it gave me undefined

var country = {"visited1":"106","visited2":"107","visited3":"104"};
for (i=1; i<3; i++){


     $('#viewer' +i).append('<tr><td id="viewer"+i>'+country.visited+i+'</td></tr>');
    }

Please advice

1 Answer

Jamie Weir
Jamie Weir
4,241 Points

Try replacing country.visited+i with country["visited"+i]. This is another way to call a value from an object.

If you don't need anything more complex than an ordered series of values, you could also use an array instead of an object, such as var countryvisited = ["106","107","104"] And then call it in the loop with countryvisited[i].

Just make sure you start the counter from 0 if you are using an array.

Iain Simmons
Iain Simmons
Treehouse Moderator 32,305 Points

Also, the current loop with a JavaScript object will only run through twice, and won't include the third key/value in the object.

It should be either i < 4 or i <= 3 —sorry, no love heart in this case! :)

Jackie Jen
Jackie Jen
2,723 Points

Thanks Jamie & Simmons.

It works!!