Retrieve Value Using Key in Associative Array

Question

I have an array into which I insert a load of values along with their corresponding keys. They are inserted fine as I can see them all in the array when I do a console.log.

The issue is, I can't seem to retrieve the values from the array using their respective keys.

Here is my code.

var personArray = [];
personArray.push({
 key: person.id,
 value:person
});
var personID = person.id;
console.log(personArray.personID);

I have also tried console.log(personArray[personID]; but this does not work either.

The value I get in my console is undefined.

Answer 1

What you are doing is that you push dictionaries into the array. If person.id is unique, then you can do this:

var personDict = {}
personDict[person.id] = person

and then personDict[personID] will work. If you want to keep your structure, then you have to search inside the array for it:

var personArray = [];
personArray.push({
 key: person.id,
 value:person
});
var personID = person.id;
var search = function(id) {
 var l = personArray.length;
 for (var i = 0; i < l; i++) {
 var p = personArray[i];
 if (p.key === id) {
 return p.value;
 }
 }
 return null;
};
search(personID);

• StuStirling: Thank you. New to javascript so still struggling with syntax

Answer 2

You can use dictionary format as suggested by @freakish, Or use the filter function to find the required object.

For example:

var personArray = [];
var person = {id: 'aki', value:'Akhil'}
personArray.push({
 key: person.id,
 value:person
});
personArray.filter(function(item){
 return item.key == 'aki'
});