Question 188862 in Javascript Question posted in
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Javascript ES6 replace null with empty string in a nested array

I have a dynamic array which can have n number of sections/fields as below.

[
    {
        "id": "section-1",
        "fields": [{
                "id": "field1",
                "value": "A1"
            }, {
                "id": "field2",
                "value": null
            }
        ]
    }, {
        "id": "section-2",
        "fields": [{
                "id": "field3",
                "value": null
            }, {
                "id": "field4",
                "value": null
            }
        ]
    }, {
        "id": "section-3",
        "fields": [{
                "id": "field5",
                "value": "A5"
            }
        ]
    }
]

Can I use ES6 to update any null values to empty string in this array. So the output would be the same exact structure replacing any "value": null with "value": ""

Tags:

2

Answers


  1. 0

    Nested forEach() calls:

    const data = [{
  "id": "section-1",
  "fields": [{
    "id": "field1",
    "value": "A1"
  }, {
    "id": "field2",
    "value": null
  }]
}, {
  "id": "section-2",
  "fields": [{
    "id": "field3",
    "value": null
  }, {
    "id": "field4",
    "value": null
  }]
}, {
  "id": "section-3",
  "fields": [{
    "id": "field5",
    "value": "A5"
  }]
}];

data.forEach(section => section.fields.forEach(field => {
  if (field.value === null) {
    field.value = "";
  }
}));

console.log(data);
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  2. 0

    You can use a pretty simple neat trick using JSON.parse and JSON.stringify using reviver parameter as:

    It will replace null with "" doesn’t matter how nested object it is.

    JSON.parse(JSON.stringify(obj), (key, value) => value === null ? "": value)

    const obj = [
    {
        "id": "section-1",
        "fields": [{
            "id": "field1",
            "value": "A1"
        }, {
            "id": "field2",
            "value": null
        }
        ]
    }, {
        "id": "section-2",
        "fields": [{
            "id": "field3",
            "value": null
        }, {
            "id": "field4",
            "value": null
        }
        ]
    }, {
        "id": "section-3",
        "fields": [{
            "id": "field5",
            "value": "A5"
        }
        ]
    }
]

const result = JSON.parse(JSON.stringify(obj), (key, value) => value === null ? "": value)
console.log(result);
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