Iterating Array of Objects in javascript

Question

I am having an array that consists the objects with a key, value how can we iterate each object for caste and id.

[
 Object {
 caste = "Banda",
 id = 4
 },
 Object {
 caste = "Bestha", 
 id = 6
 }
]

• Salvatorelab: iterate over the array of objects? iterate over object fields? both?
• sasi: iterate over array of objects ..

Answer 1

Using jQuery.each():

var array = [
 {caste: "Banda", id: 4},
 {caste: "Bestha", id: 6}
];
 
$.each(array, function( key, value ) {
 console.log('caste: ' + value.caste + ' | id: ' +value.id);
}
);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

• RRikesh: How? I didn't understand what you meant.
• sasi: for the first iteration it gives me banda and 4 for the second iteration it again gives banda and 4 ,bestha and 6 like that..
• Gustavo Carvalho: As TheBronx said see his answer, its just an array. Since that solution uses native Javascript, it might be a better design if you don't want do use jQuery in your project.
• RRikesh: The question was tagged with jquery, I though OP wanted a jQuery answer. Or course vanilla JS is faster.

Answer 2

Example code:

var list = [
 { caste:"Banda",id:4},
 { caste:"Bestha",id:6},
];
 
for (var i=0; i<list.length; i++) {
 console.log(list[i].caste);
}

It's just an array, so, iterate over it as always.

Answer 3

In plain JavaScript you can do this:

var array = [{caste: "Banda", id: 4}, {caste: "Bestha", id:6}];
array.forEach(function(element, index) {
 console.log(element.id+" "+element.caste);
});

The callback function is called with a third parameter, the array being traversed. For learn more!

So, you don't need to load jQuery library.

Greetings.

Answer 4

var array = [{caste: "Banda", id: 4}, {caste: "Bestha", id:6}];
var length = array.length;
for (var i = 0; i < length; i++) {
 var obj = array[i];
 var id = obj.id;
 var caste = obj.caste;
}

Answer 5

Arrow functions are modern these days

Using jquery $.each with arrow function

 var array = [
 {caste: "Banda", id: 4},
 {caste: "Bestha", id: 6}
 ];
 $.each(array, ( key, value ) => {
 console.log('caste: ' + value.caste + ' | id: ' +value.id);
 });

Using forEach with arrow function

 array.forEach((item, index) => {
 console.log('caste: ' + item.caste + ' | id: ' +item.id);
 });

Using map with arrow function. Here map returns a new array

 array.map((item, index) => {
 console.log('caste: ' + item.caste + ' | id: ' +item.id);
 });

Answer 6

The forEach loop accepts an iterator function and, optionally, a value to use as "this" when calling that iterator function.

 var donuts = [
 { type: "Jelly", cost: 1.22 },
 { type: "Chocolate", cost: 2.45 },
 { type: "Cider", cost: 1.59 },
 { type: "Boston Cream", cost: 5.99 }
];
donuts.forEach(function(theDonut, index) {
 console.log(theDonut.type + " donuts cost $"+ theDonut.cost+ " each");
});

Subsequently it can also be broken down to this

var donuts = [
 { type: "Jelly", cost: 1.22 },
 { type: "Chocolate", cost: 2.45 },
 { type: "Cider", cost: 1.59 },
 { type: "Boston Cream", cost: 5.99 }
];
function ShowResults(donuts) { 
 console.log(donuts.type + " donuts cost $"+ donuts.cost+ " each"); 
}
donuts.forEach(ShowResults);

Answer 7

you can use jquery to iterate through all the objects jQuery wants you to fill a callback function, which jquery will call back. The first input parameter will be given the key and the second input parameter the value:

$.each(dataList, function(index, object) {
 $.each(object,function(attribute, value){
 alert(attribute+': '+value);
 });
});

documentation: http://api.jquery.com/jQuery.each/

• Seralto: The fourth line should be });

Answer 8

Use jQuery.each:

$.each([your array of objects], function(index, value) {
 // Do what you need, for example...
 alert(index + ': ' + value);
});

Answer 9

To iterate over an array filled with stuff in jQuery use $.each, to iterate over an Object for its properties use for..in