How to convert all the blank values of a JSON object to hyphens?

Question

Here is my sample response:

var jsonData1 = [{
  firstName: "Sam",
  age: "10"
}, {
  firstName: "John",
  age: "11"
}, {
  firstName: "Jack",
  age: "12"
}, {
  firstName: "Pam",
  age: "13"
}, {
  firstName: "",
  age: "14"
}, {
  firstName: "Mitch",
  age: ""
}];

All I want is, wherever I have a blank string in any field, to show it as zero. I want to do it using plain JS, no lodash, no jQuery.

Please learn [the difference between JSON and Object Literal Notation](https://stackoverflow.com/questions/2904131/what-is-the-difference-between-json-and-object-literal-notation). — str, Jan 28 '19 at 14:18

idmean · Answer 1 · 2019-01-28T14:26:09.910

1

You can write this in one line of code:

jsonData1.forEach(o => Object.keys(o).forEach(key => o[key] === '' && (o[key] = '-')))

edited Jan 28 '19 at 14:26

answered Jan 28 '19 at 14:19

idmean

14,540
9
54
83

This won't work - `Object.keys()` takes an object, not a function. – Duncan Thacker Jan 28 '19 at 14:20
I want old es5 syntax, using plain for loops – tommy123 Jan 28 '19 at 14:22
Looks better! I would recommend using triple equals comparison instead of double equals to avoid accidental type coercion though. – Duncan Thacker Jan 28 '19 at 14:23

score 1 · Answer 2 · answered Jan 28 '19 at 14:20

1

Assuming the given data structure, I'd approach it like this:

loop through the elements in the array with Array.forEach()
loop through the properties in the element with Object.keys(person).forEach()
check for emptystring and replace

Like this:

jsonData1.forEach(person => {
     Object.keys(person).forEach(key => {
         if (person[key] === "") person[key] = "-";
     });
});

answered Jan 28 '19 at 14:20

Duncan Thacker

5,073
1
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I want to write in old JS style with just for loops – tommy123 Jan 28 '19 at 14:23
Are you sure? I never use `for` anymore - it's too fiddly. But if you want! – Duncan Thacker Jan 28 '19 at 14:25

Maheer Ali · Answer 3 · 2019-01-28T14:34:13.373

0

jsonData1 = jsonData1.map(item=>{
    for(let key in item){
        if(item[key].length === 0) item[key] = 0;
    }
    return item;
})

With Simple Loop

for(let i = 0; i<data.length;i++){
    let keys = Object.keys(data[i]); //returns an array of keys of object
    for(let key = 0;key<keys.length;key++){ 
        let keyName = keys[key];
        if(data[i][keyName].length === 0) data[i][keyName] = 0
    }
}

edited Jan 28 '19 at 14:34

answered Jan 28 '19 at 14:20

Maheer Ali

35,834
5
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This is a bit too eager - you'll also replace empty arrays, which isn't what the questioner wanted. – Duncan Thacker Jan 28 '19 at 14:24
I want to write in old syntax using plain for loop – tommy123 Jan 28 '19 at 14:24

Beppo · Answer 4 · 2019-01-28T14:26:12.703

0

As you do have an array, you can simply iterate over it:

for (var i=0;i<jsonData1.length;i++) {
    if (jsonData1[i].age==="")
        jsonData1[i].age = 0;
    if (jsonData1[i].firstName==="")
        jsonData1[i].firstName = "Unknown";
}

edited Jan 28 '19 at 14:26

answered Jan 28 '19 at 14:20

Beppo

176
7

This doesn't cover the case for firstName – chazsolo Jan 28 '19 at 14:21
I'm afraid this won't work - jsonData[i].age.length is a number, so will never be equal to "". – Duncan Thacker Jan 28 '19 at 14:21
Looks better, although the `Unknown` seems to come out of nowhere! – Duncan Thacker Jan 28 '19 at 14:27
Of course you both are right, fixed, thanks! I got mixed uo when going from the ' .length===0 ' to the ' =="" ' approach. The firstName thing i missed because setting a name to zero didn't fit my mind ;-) - for the general approach, please refer to the other answers. – Beppo Jan 28 '19 at 14:29

Mamun · Answer 5 · 2019-01-28T14:26:40.933

You can use for...of

The for...of statement creates a loop iterating over iterable objects, including: built-in String, Array, Array-like objects (e.g., arguments or NodeList), TypedArray, Map, Set, and user-defined iterables.

var jsonData1 = [{
  firstName: "Sam",
  age: "10"}, {
  firstName: "John",
  age: "11"},{
  firstName: "Jack",
  age: "12"},{
  firstName: "Pam",
  age: "13"},{
  firstName: "",
  age: "14"},{
  firstName: "Mitch",
  age: ""
}];

for(var p of jsonData1){
  if(p.firstName.trim()=="") p.firstName="0";
  if(p.age.trim()=="") p.age="0"
}

console.log(jsonData1);

I want to write in old syntax, plain for loops – tommy123 Jan 28 '19 at 14:24 — tommy123, Jan 28 '19 at 14:24

elraphty · Answer 6 · 2019-01-28T14:28:03.490

0

Try this

 let newData = jsonData1.forEach(function(data) {
     for(ans in data) {
        If(data[ans] === "") data[ans] = 0;
     }
  });

edited Jan 28 '19 at 14:28

answered Jan 28 '19 at 14:22

elraphty

630
6
13

score 0 · Answer 7 · answered Jan 28 '19 at 14:22

Using forEach loop

var jsonData1 = [
 {
firstName: "Sam",
age: "10"
  },
 {
firstName: "John",
age: "11"
  },
 {
firstName: "Jack",
age: "12"
  },
  {
firstName: "Pam",
age: "13"
  },
  {
firstName: "",
age: "14"
 },
 {
firstName: "Mitch",
age: ""
}
 ];
 jsonData1.forEach((e)=>{Object.keys(e).forEach((x)=>e[x]==""?e[x]=0:false)})
 console.log(jsonData1)

score 0 · Answer 8 · answered Jan 28 '19 at 14:25

That should do the trick for nested objects:

const convertObj = obj => {
    Object.keys(obj).forEach(key => {
        if (obj[key] === '') {
            obj[key] = 0
        } else if (obj[key] instanceof Object) {
            convertObj(obj[key])
        }
    })

    return obj
}

Sample test:

const jsonData1 = [
   {
        firstName: "Mitch",
        age: "",
        nested_test: [
            {
                foo: 'bar',
                age: ''
            }
        ],
        nested_object: {
            foo: 'bar',
            age: ''
        }
    }
]

Result:

[
  {
    "firstName": "Mitch",
    "age": 0,
    "nested_array": [
      {
        "foo": "bar",
        "age": 0
      }
    ],
    "nested_object": {
      "foo": "bar",
      "age": 0
    }
  }
]

How to convert all the blank values of a JSON object to hyphens?

8 Answers8