Javascript remove object that doesn't meet requirements

JavaScript
#1

Hello, I have an object that contains an array of objects, and I would like to check inside every object of the array if the item “json_formatted” exists before doing operations.

My code:

var obj1 = { model: "500", color: "white", constructor: { skill: { json_formatted: "{\"irregular\":{\"pulse_quality\":[255,0],\"pulse\":[91,0]}}" } } };
var obj2 = { model: "200", color: "black", constructor: { skill: { json_formatted: "{\"irregular\":{\"pulse_quality\":[255,0,255,500,255,1001,255,1504,255,2007,255,2512,255,3015,255,3517,255,4018,255,4521,255,5024,255,5530,255,6033,255,6534,255,7036,255,7539,255,8043,255,8547,255,9049,255,13208,255,13741,255,14243,255,14745,255,15284,255,15827,255,16367,255,16910,255,17450,255,17991,255,18533,255,19075,255,19616,255,20157,255,20659,255,21199,255,21742,255,22282,255,22823,255,23366,255,23909,255,24449,255,24990,255,25532,255,26073,255,26616,255,27156,255,27657,255,28158,255,28699,255,29239,255,29782,255,30322,255,30865,255,31366,255,31905,255,32448,255,32949,255,33488,255,34031,255,34571,255,35115,255,35654,255,36155,255,36698,255,37237,255,37781,255,38320,255,38864,255,39403,255,39947,255,40487,255,41030,255,41570,255,42114,255,42653,255,43197,255,43736,255,44280,255,44819,255,45363,255,45902,255,46446,255,46984,255,47485,255,48029,255,48568,255,49113,255,49651,255,50195,255,50734,255,51279,255,51817,255,52360,255,52862,255,53400,255,53945,255,54483,255,54984,255,55527,255,56066,255,56612,255,57149,255,57694,255,58194,255,58733,255,59277,255,59816],\"pulse\":[77,0,77,500,77,1001,77,1504,77,2007,77,2512,77,3015,77,3517,77,4018,77,4521,77,5024,77,5530,77,6033,77,6534,77,7036,77,7539,77,8043,77,8547,74,9049,74,13208,74,13741,74,14243,74,14745,79,15284,79,15827,79,16367,79,16910,79,17450,79,17991,79,18533,79,19075,79,19616,79,20157,81,20659,81,21199,81,21742,81,22282,81,22823,78,23366,78,23909,78,24449,78,24990,78,25532,80,26073,80,26616,80,27156,80,27657,80,28158,80,28699,80,29239,80,29782,80,30322,80,30865,83,31366,83,31905,83,32448,83,32949,83,33488,83,34031,82,34571,82,35115,82,35654,82,36155,82,36698,82,37237,82,37781,82,38320,82,38864,82,39403,82,39947,82,40487,82,41030,82,41570,82,42114,82,42653,82,43197,82,43736,82,44280,82,44819,82,45363,82,45902,82,46446,82,46984,82,47485,82,48029,82,48568,82,49113,82,49651,82,50195,82,50734,82,51279,82,51817,82,52360,82,52862,82,53400,82,53945,82,54483,82,54984,82,55527,82,56066,82,56612,82,57149,82,57694,82,58194,82,58733,82,59277,82,59816]}}" } } };
var obj3 = { model: "600", color: "orange", constructor: { skill: {} } };
var obj4 = { model: "100", color: "red", constructor: { skill: { json_formatted: "{\"irregular\":{\"pulse_quality\":[255,0],\"pulse\":[21,0]}}" } } };
var obj5 = { model: "900", color: "blue", constructor: { skill: { json_formatted: "{\"irregular\":{\"pulse_quality\":[255,0],\"pulse\":[99,0]}}" } } };

var multiobject = {obj1, obj2, obj3, obj4, obj5};

var edge = [];

Object.keys(multiobject).map(function(objectKey, index) {
    var value = multiobject[objectKey].constructor.skill.json_formatted;
    var ex = JSON.parse(value);
		edge.push(ex); 
});

edge.forEach((e) => {
  e.irregular.pulse = e.irregular.pulse.filter(f => f % 2 == 0);
  e.irregular.pulse_quality = e.irregular.pulse_quality.filter(f => f % 2 == 1);
})

The code actually returns an error because obj3 has no json_formatted field. I would like to check in the .map operation if the field exists before doing the operations to prevent this error from happening and only continue with the objects that have the json_formatted field.

JSFiddle - Code Playground

Thanks.

#2

I would use prop in obj to find out if the property exists in there.

Object.keys(multiobject).map(function(objectKey, index) {
    var skill = multiobject[objectKey].constructor.skill;
    var hasJsonFormatted = "json_formatted" in skill;
    if (!hasJsonFormatted) {
      return;
    }
    var value = skill.json_formatted;
    var ex = JSON.parse(value);
    edge.push(ex); 
});

Or, to avoid the negative-check in the if-condition:

Object.keys(multiobject).map(function(objectKey, index) {
    var skill = multiobject[objectKey].constructor.skill;
    if ("json_formatted" in skill) {
        var value = skill.json_formatted;
        var ex = JSON.parse(value);
        edge.push(ex); 
    }
});
#3

Thanks for the answer, @Paul_Wilkins, but still getting the error “json_formatted is not defined”

What could be causing this issue?

Edit: checking the second code, posted before your edit.

#4

Oh right, json_formatted needs to be as a string.

"json_formatted" in skill

I’ll update the code.

1 Like
#5

Works! Thank you sir @Paul_Wilkins

1 Like