2

I have a JSON object : 

[{"box":1,"parent":[],"child":[{"boxId":2}]},{"box":2,"parent":[{"boxId":1}],"child":[]}]

I have a requirement where in I would like to check whether my JSON object has particular box; if yes then check if it has particular child.

eg: check if box 1 exists if yes then check if it has child if yes then check if it has child boxId=2

How do I do that in javascript/ jquery?

This is how I tried:

   var DependantArr=myJSON;
   var $hasDependancy;
   DependantArr.map(function (boxes) {
    if (boxes.box == 2) {
        if (boxes.child.length != 0) {
           boxes.child.map(function (child) {
           $hasDependancy = true;
           return false;
         });
     }
   }

This doesn't seem to work as even after I return false it still continues to go in loop. I would like to break the loop if i find a match.

Any suggestion?

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1
  • 1
    Use a normal for-loop then, you cannot break/return from using .map(). As the return is for the current callback, not the entire operation. Commented Nov 3, 2015 at 6:56

6 Answers 6

Reset to default
2

You need to iterate over all arrays, you need.

var array = [{ "box": 1, "parent": [], "child": [{ "boxId": 2 }] }, { "box": 2, "parent": [{ "boxId": 1 }], "child": [] }];

function check() {
    var found = false;
    array.some(function (a) {
        if (a.box === 1) {
            Array.isArray(a.child) && a.child.some(function (b) {
                if (b.boxId === 2) {
                    found = true;
                    return true;
                }
            });
            return true;
        }
    });
    return found;
}

document.write(check());

Another solution features a more generic approach, with a given object, which acts as a pattern for the needed items.

[
    { condition: { box: 1 }, nextKey: 'child' },
    { condition: { boxId: 2 } }
]


var array = [{ "box": 1, "parent": [], "child": [{ "boxId": 2 }] }, { "box": 2, "parent": [{ "boxId": 1 }], "child": [] }];
    
function check(array, conditions) {

    function c(a, index) {
        var el = conditions[index],
            k = Object.keys(el.condition),
            v = el.condition[k],
            found = false;

        return Array.isArray(a) &&
            a.some(function (b) {
                if (b[k] === v) {
                    found = true;
                    if (conditions.length > index + 1) {
                        found = c(b[el.nextKey], index + 1);
                    }
                    return true;
                }
            }) &&
            found;
    }
    return c(array, 0);
}

document.write(check(array, [{ condition: { box: 1 }, nextKey: 'child' }, { condition: { boxId: 2 } }])+'<br>');
document.write(check(array, [{ condition: { box: 2 }, nextKey: 'parent' }, { condition: { boxId: 1 } }]) + '<br>');

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Comments

1

Create a function that will call the filter on your array and return it. The returned value would be an array containing the found object(s) which match(es) your condition(s).

Demo Snippet: (check the console)

var json = [{"box":1,"parent":[],"child":[{"boxId":2}]},{"box":2,"parent":[{"boxId":1}],"child":[]}];

function search(id, childId) {
    return json.filter(function(obj) {
        if ((obj.box == id) && (obj.child) && (obj.child.length > 0)) {
            return obj.child.filter(function(child) {
                return (child.boxId == childId);
            });
        }
    });
}

console.log(search('1', '2')[0]);
console.log(search('2', '2')[0]);

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2 Comments

"check if it has child boxId=2"
Thanks @Ziki. I completely missed that part. Updated.
1

You can make use of recursion. call the same function recursively to check if the element you need is really exist in the array or not. 

var json = [{"box":1,"parent":[],"child":[{"boxId":2}]},{"box":2,"parent":[{"boxId":1}],"child":[]}];

var found = false;
function validateJson(data, box, boxId){
  for(key in data){
    if((data[key].constructor === Object || data[key].constructor === Array) && (key !== box && data[key] !== 1 || key !== boxId && data[key] !== 2)){
      arguments.callee(data[key]); // <---calls the same function again.
    } else {
      found = true; // true only in the case of if "box":1 and "boxId" : 2
    }
  }
  return found;
}
var result = validateJson(json, "box", "boxId");
document.body.innerHTML = '<pre> found : '+JSON.stringify(result) + '</pre>';

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Comments

0

Try this

data.forEach(function (el) {
 Object.keys(el).forEach(function (property) {
  if (el[property] === 'your  value to check') {
      // do whatever you need here
    }
  });
});
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Comments

-1

If this is the only case you need to check, you can use this:

var DependantArr = [{"box": 1, "parent": [], "child": [{"boxId": 3}]}, {"box": 2, "parent": [{"boxId": 1}], "child": []}];
var $hasDependancy = DependantArr.some(function(thisBox) {
    if ((thisBox.box === 1) && (thisBox.hasOwnProperty('child'))) {
        return thisBox.child.filter(function(thisChild) {
            return thisChild.boxId === 2;
        }).length > 0;
    }
});
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Comments

-1

I think these will help. 

  for(var i=DependantArr.length;i>=0;i--) {
                     return DependantArr[i].box == 1 &&  DependantArr[i].child.length!=0 &&
     DependantArr[i].child[0].boxId==2;

            }
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1 Comment

check if it has child boxId=2, And you have a lot of mistakes in your code like: DependantArr[i].box.length

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