How to insert new value into array as per key value using Javascript

Question

I need one help. I need to insert one new value into existing array by matching the key value using Javascript.I am explaining the scenario below.

var galArr=[
     {'image':'12.png','comment':'hii','act':'edit'},
     {'image':'13.png','comment':'hello','act':'edit'},
     {'image':'14.png','comment':'hee','act':'edit'},
]

The above is my existing array.I need to match with the below another array.

var arr=[
    {'image':'12.png','comment':'hii'},
    {'image':'14.png','comment':'hee'},
]

Here i need to match the array arr with an array galArr if image name will same this checked:true will add in the rective row of existing array galArr . Suppose arr[0].image==galArr[0].image then checked:true will add in that respective row of existing array. Please help me.

Answer 1

This should be sufficient.

 var galArr=[ {'image':'12.png','comment':'hii','act':'edit'}, {'image':'13.png','comment':'hello','act':'edit'}, {'image':'14.png','comment':'hee','act':'edit'}, ]; var arr=[ {'image':'12.png','comment':'hii'}, {'image':'14.png','comment':'hee'}, ]; // start looping over `arr` arr.forEach(function(o, i){ // now loop over `galArr` to find match galArr.forEach(function(gO, i){ // when there is a match if(o.image == gO.image){ console.log(gO); // add checked property to this object gO['checked'] = true; } }); }); // Output console.log(galArr); 

Answer 2

First of all check condition and if the condition match then create a new temp json and replace it with old json

 arr.forEach(function(d){
       galArr.forEach(function(e){
            if(e.image==d.image){
               temp = {};
               temp.image = e.image;
               temp.comment = e.comment;
               temp.checked = e.comment;
               temp.action = e.action;
               e = temp;
            }
       });
    });

Answer 3

I would create an image index, where its indexes would be the whole image file names and later I would use that image index to quickly check and add checked property to galArr array:

 var galArr=[ {'image':'12.png','comment':'hii','act':'edit'}, {'image':'13.png','comment':'hello','act':'edit'}, {'image':'14.png','comment':'hee','act':'edit'}, ]; var imageIndex = galArr.map(function(item) { return item.image; }); var arr=[ {'image':'12.png','comment':'hii'}, {'image':'14.png','comment':'hee'}, ] arr.forEach(function(item) { item.checked = imageIndex.indexOf(item.image) > -1; }); 

If your users will use your JavaScript code within a modern Web browser, I would use the new Set collection :

 var galArr=[ {'image':'12.png','comment':'hii','act':'edit'}, {'image':'13.png','comment':'hello','act':'edit'}, {'image':'14.png','comment':'hee','act':'edit'}, ]; var imageIndex = galArr.reduce(function(result, item) { result.add(item.image); return result; }, new Set()); var arr=[ {'image':'12.png','comment':'hii'}, {'image':'14.png','comment':'hee'}, ] arr.forEach(function(item) { item.checked = imageIndex.has(item.image); }); 

I've asked a question to assist everyone in understanding how valueable are sets : Is Set a hashed collection in JavaScript?