CODEWITHSUNDEEP
javascriptjquery
user3399326
user3399326

Reputation: 973

replace value if key is same in json object

I have following array which consist of json objects:

items = [{"Id":"car","color":"blue"},{"Id":"truck","color":"red"}]

I have new json object. If the "Id" of this object(newItem) matches the "Id" in items, i would like to replace the "color" value.

newItem = {"Id":"car","color":"yellow"}

So, i would like output like this: 

items = [{"Id":"car","color":"yellow"},{"Id":"truck","color":"red"}]

Here's what i have so far:

for (var i=0; i<items.length; i++) {
    var x = items[i];

    if(x.Id == newItem.Id){    //first check if id matches  
        if (JSON.stringify(items[i]) == JSON.stringify(newItem))  { 
            alert('objects are same');                        
            return ;           
        } 
        else {
            var newColor = JSON.stringify(x).replace(x.color, newItem.color);
            alert(JSON.parse(newColor));

        }
    }            
}

Upvotes: 6

Views: 25537

Answers (6)

arahr26
arahr26

Reputation: 21

The Underscore.js library isn't strictly necessary for this specific problem, but it's great for dealing with collections.

var items = [{"Id":"car","color":"blue"},{"Id":"truck","color":"red"}];
var newItem = {"Id":"car","color":"yellow"};

_.each(items, function(item) {
  if (item.Id === newItem.Id) item.color = newItem.color
});

Upvotes: 2

Alexandru Pufan
Alexandru Pufan

Reputation: 1912

Here's a way to do it, using jQuery:

var items = [
  {"Id": "car", "color": "blue"},
  {"Id": "truck", "color": "red"}
];

var newItem = {
  "Id": "car",
  "color": "yellow"
};


$(items).each(function(item) {
  if ($(this)[0].Id == newItem.Id) {
    $(this)[0].color = newItem.color
  }
});

Upvotes: 2

Pritam Banerjee
Pritam Banerjee

Reputation: 18923

The following code should work for you. You can exit the loop once the id is matched. A little better performance wise.

items = [{"Id":"car","color":"blue"},{"Id":"truck","color":"red"}];

newItem = {"Id":"car","color":"yellow"};

for (var i = 0; i < items.length; i++){
    if (newItem.id == items[i].id ){
        items[i].color = newItem.color;
        break;
    }
}

Upvotes: 2

Pavan Ravipati
Pavan Ravipati

Reputation: 1870

Working JSFiddle. Here's one way to do it by using .forEach from Array.prototype.forEach: 

var items = [{"Id":"car","color":"blue"},{"Id":"truck","color":"red"}];
var newItem = {"Id":"car","color":"yellow"}

items.forEach(function(item) {
  if (newItem.Id === item.Id) {
    item.color = newItem.color
  }
});

Upvotes: 9

Joy
Joy

Reputation: 9550

Check working demo: JSFiddle.

Using Array.prototype.map is concise and clear:

items.map(function(obj) {
    (obj.Id === newItem.Id) && (obj.color = newItem.color);
});

Upvotes: 2

GPicazo
GPicazo

Reputation: 6676

Try this:

items.forEach(function(item) {
    if(item.Id == newItem.Id && item.color != newItem.color){
        item.color = newItem.color;
    }            
});

Upvotes: 4

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