Switch up the key while iterating through a JSON object

Question

Switch up the key while iterating through a JSON object

Can you modify the key while iterating through objects using an external variable? Picture it like this:

var data = [{
    "id": 1,
    "name": "Simon",
    "age": 13
}, {
    "id": 2,
    "name": "Helga",
    "age": 18
}, {
    "id": 3,
    "name": "Tom",
    "age": 27
}, ]

var key = name;

for (var i = 0; i < data.length; i++) {
    var output = data[i].key;
}

However, this currently results in an undefined output. The aim is to create a function that can manage various types of loops.

javascript arrays json for-loop

Answer 1

Answer №1

To access objects in JavaScript, you can use a similar syntax to arrays. Here is an example of the code you need:

var data = [{
    "id": 1,
    "name": "Simon",
    "age": 13
}, {
    "id": 2,
    "name": "Helga",
    "age": 18
}, {
    "id": 3,
    "name": "Tom",
    "age": 27
}]

var key = "name";

for (var i = 0; i < data.length; i++) {
    var output = data[i][key];
}

In regard to the now-deleted previous answer, I suggest avoiding using foreach since it is not compatible with Internet Explorer 8.

Instead, consider using:

var key = "name";

for (var i in data) {
  if(data.hasOwnProperty(i))
  {
    var output = data[i][key];
  }
}

Answer 2

To access objects in JavaScript, you can use a similar syntax to arrays. Here is an example of the code you need:

var data = [{
    "id": 1,
    "name": "Simon",
    "age": 13
}, {
    "id": 2,
    "name": "Helga",
    "age": 18
}, {
    "id": 3,
    "name": "Tom",
    "age": 27
}]

var key = "name";

for (var i = 0; i < data.length; i++) {
    var output = data[i][key];
}

In regard to the now-deleted previous answer, I suggest avoiding using foreach since it is not compatible with Internet Explorer 8.

Instead, consider using:

var key = "name";

for (var i in data) {
  if(data.hasOwnProperty(i))
  {
    var output = data[i][key];
  }
}

Answer 3

Answer №2

A possible solution to your problem could be a function similar to the one below:

function extractValueFromArray(array, value) {
    for (var idx in array) {
        //perform actions using array[idx][value]
    }
}

To use this function, simply call it with the desired parameters like so:

extractValueFromArray(data, "title")

This function is designed to handle the extraction of specific values from an array of objects. It can be customized further according to specific requirements, but I've kept it concise for simplicity.

Answer 4

A possible solution to your problem could be a function similar to the one below:

function extractValueFromArray(array, value) {
    for (var idx in array) {
        //perform actions using array[idx][value]
    }
}

To use this function, simply call it with the desired parameters like so:

extractValueFromArray(data, "title")

This function is designed to handle the extraction of specific values from an array of objects. It can be customized further according to specific requirements, but I've kept it concise for simplicity.

Switch up the key while iterating through a JSON object

Answer №1

Answer №2

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