Parse the value of a JSON object from a string within an array and convert it to a number using float

Question

Parse the value of a JSON object from a string within an array and convert it to a number using float

I have an array containing JSON objects. Some of the properties' values in these objects need to be converted from strings to numbers. The goal is to create a new list with the modified JSON objects that have the number values. I attempted to use parseFloat for this task, but it was not successful. code

var json = [{
    "id" : "0", 
    "msg"   : "hi",
    "cost" : "250.24",
    "discount": "10"
},
{
    "id" : "1", 
    "msg"   : "there",
    "cost" : "45.00",
    "discount": "0"
}];

var  json1 = [];

for (var key in json) {
       if (json.hasOwnProperty(key)) {
    
          for (const prop in json[key]) {        
          const parsed = parseFloat(json[key][prop]);              
          res[key][prop] = isNaN(parsed) ? json[key][prop] : parsed;                                        
           //  need to  push  array of modified json object value converted to number from string into json1  
          }
         
       }
    }

javascript arrays json

Answer 1

Answer №1

your loop seems to be incorrect.

for (var key in json) => if you are looping over an array, it will return the item index instead of the key

json.hasOwnProperty(key) => since your json is actually an array, there is no need to use hasOwnProperty which is typically used for object

I have provided 2 alternatives for you:

*: you can use + to convert a string to a number.

*: if you wish to iterate over item keys, you can utilize way1 and explore methods like Object.entries, Object.keys, and Object.values.

const json = [{
    "id": "0",
    "msg": "hi",
    "cost": "250.24",
    "discount": "10"
},
{
    "id": "1",
    "msg": "there",
    "cost": "45.00",
    "discount": "0"
}];

//way1
const json1 = json.map((item)=>{
    return Object.entries(item).reduce((pre,[key,value])=>{
        const parsed = +value
        pre[key] = isNaN(parsed) ? value : parsed
        return pre
    },{})
})
console.log('json1',json1)

//way2
const json2 = json.map((item)=>{
    return {
        "id": +item.id,
        "msg": item.msg,
        "cost": +item.cost,
        "discount": +item.discount,
    }
})
console.log('json2',json2)

Answer 2

your loop seems to be incorrect.

for (var key in json) => if you are looping over an array, it will return the item index instead of the key

json.hasOwnProperty(key) => since your json is actually an array, there is no need to use hasOwnProperty which is typically used for object

I have provided 2 alternatives for you:

*: you can use + to convert a string to a number.

*: if you wish to iterate over item keys, you can utilize way1 and explore methods like Object.entries, Object.keys, and Object.values.

const json = [{
    "id": "0",
    "msg": "hi",
    "cost": "250.24",
    "discount": "10"
},
{
    "id": "1",
    "msg": "there",
    "cost": "45.00",
    "discount": "0"
}];

//way1
const json1 = json.map((item)=>{
    return Object.entries(item).reduce((pre,[key,value])=>{
        const parsed = +value
        pre[key] = isNaN(parsed) ? value : parsed
        return pre
    },{})
})
console.log('json1',json1)

//way2
const json2 = json.map((item)=>{
    return {
        "id": +item.id,
        "msg": item.msg,
        "cost": +item.cost,
        "discount": +item.discount,
    }
})
console.log('json2',json2)

Answer 3

Answer №2

Objects Transformation

I find using a map function for object transformation more efficient:

var json = [{
    "id": "0",
    "msg": "hi",
    "cost": "250.24",
    "discount": "10"
  },
  {
    "id": "1",
    "msg": "there",
    "cost": "45.00",
    "discount": "0"
}];

const transformedJson = json.map(obj =>
  Object.fromEntries(Object.entries(obj).map(([key, value]) => {
    const parsedValue = parseFloat(value);
    return [
      key,
      isNaN(parsedValue) ? value : parsedValue
    ];
  }));

console.log(transformedJson);

If you prefer traditional loops:

var json = [{
    "id": "0",
    "msg": "hi",
    "cost": "250.24",
    "discount": "10"
  },
  {
    "id": "1",
    "msg": "there",
    "cost": "45.00",
    "discount": "0"
}];

const transformedJson = [];

for (const obj of json) {
  const mappedObj = {};

  for (const [key, value] of Object.entries(obj)) {
    const parsedValue = parseFloat(value);
    mappedObj[key] = isNaN(parsedValue) ? value : parsedValue;
  }

  transformedJson.push(mappedObj);
}

console.log(transformedJson);

Arrays Conversion

var json = [[
    {key:"id", value:"0"},
    {key:"msg", value:"hi"},
    {key:"cost", value:"250.24"},
    {key:"discount", value:"10"}
  ],
  [
    {key:"id", value:"1"},
    {key:"msg", value:"there"},
    {key:"cost", value:"45.00"},
    {key:"discount", value:"0"}
]];

const convertedJson = json.map(obj =>
  obj.map(({key, value}) => {
    const parsedValue = parseFloat(value);
    return {
      key,
      value: isNaN(parsedValue) ? value : parsedValue
    };
  });

console.log(convertedJson);

Answer 4

Objects Transformation

I find using a map function for object transformation more efficient:

var json = [{
    "id": "0",
    "msg": "hi",
    "cost": "250.24",
    "discount": "10"
  },
  {
    "id": "1",
    "msg": "there",
    "cost": "45.00",
    "discount": "0"
}];

const transformedJson = json.map(obj =>
  Object.fromEntries(Object.entries(obj).map(([key, value]) => {
    const parsedValue = parseFloat(value);
    return [
      key,
      isNaN(parsedValue) ? value : parsedValue
    ];
  }));

console.log(transformedJson);

If you prefer traditional loops:

var json = [{
    "id": "0",
    "msg": "hi",
    "cost": "250.24",
    "discount": "10"
  },
  {
    "id": "1",
    "msg": "there",
    "cost": "45.00",
    "discount": "0"
}];

const transformedJson = [];

for (const obj of json) {
  const mappedObj = {};

  for (const [key, value] of Object.entries(obj)) {
    const parsedValue = parseFloat(value);
    mappedObj[key] = isNaN(parsedValue) ? value : parsedValue;
  }

  transformedJson.push(mappedObj);
}

console.log(transformedJson);

Arrays Conversion

var json = [[
    {key:"id", value:"0"},
    {key:"msg", value:"hi"},
    {key:"cost", value:"250.24"},
    {key:"discount", value:"10"}
  ],
  [
    {key:"id", value:"1"},
    {key:"msg", value:"there"},
    {key:"cost", value:"45.00"},
    {key:"discount", value:"0"}
]];

const convertedJson = json.map(obj =>
  obj.map(({key, value}) => {
    const parsedValue = parseFloat(value);
    return {
      key,
      value: isNaN(parsedValue) ? value : parsedValue
    };
  });

console.log(convertedJson);

Parse the value of a JSON object from a string within an array and convert it to a number using float

Answer №1

Answer №2

Objects Transformation

Arrays Conversion

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