Accessing a JSON property (String) using a variable

Question

I'm trying to access a JSON using a variable I'm passing through a function:

function highlightCategory (category) {
   for (var i in data) {
      console.log(data[i].category)
   }
}

Obviously, this doesn't work, because 'category' is what I'm passing with the function and not the real name of the property, but I've been trying different possibilities unsuccessfully. Thanks in advance!

Answer 1

data[i][category]

in JS, obj.prop is synonymous with obj['prop'].

var foo = {
  bar: 'baz'
};
// foo.bar == foo['bar'] == 'baz'

Also, you're dealing with a javascript object, not JSON (though it may have originated there)

Update for those coming across this and using ES6, you can now use variables during assignment:

const propName = 'bar';
const foo = {
  [propName]: 'baz',
}
// foo.bar == foo[propName] == 'baz'

For reference, this is considered a ComputedPropertyName under Object Initializer section of ES6 spec.