如何更改数组内 object 的属性值

Question

I am trying to change the value of property of object which is inside the array and that array also inside one object.

I write below code to resolve issue however it take only last value.

my code

 var arr = [{ QUALITYNAME: "Berry Fancy", RATES: [{ "UNIT": "LB", "CURRENCY": "USD", "VALUE": 6.205240232694746 }] }, { QUALITYNAME: "Berry USDA", RATES: [{ "UNIT": "LB", "CURRENCY": "USD", "VALUE": 5.622770183585882 }] } ]; var value_a1 = null for (let i = 0; i < arr.length; i++) { var result = arr[i].RATES; var QUALITYNAME = arr[i].QUALITYNAME; console.log("result", result); result.forEach((element, index) => { value_a1 = element.VALUE; value_a1 = parseFloat(value_a1.toFixed(2)) console.log('value_a1', value_a1); }); } arr.forEach(function(item, index) { arr[index] = { QUALITYNAME: QUALITYNAME, RATES: { "UNIT": "LB", "CURRENCY": "USD", "VALUE": value_a1 } }; }); console.log(arr);

which give me output as

 result arr = [ { QUALITYNAME: 'Berry USDA',
        RATES: { UNIT: 'LB', CURRENCY: 'USD', VALUE: 5.62 } },
      { QUALITYNAME: 'Berry USDA',
        RATES: { UNIT: 'LB', CURRENCY: 'USD', VALUE: 5.62 } } ]

however I need it first value also to be there in result as below

 result arr = [ { QUALITYNAME: 'Berry Fancy',
        RATES: { UNIT: 'LB', CURRENCY: 'USD', VALUE: 6.21 } },
      { QUALITYNAME: 'Berry USDA',
        RATES: { UNIT: 'LB', CURRENCY: 'USD', VALUE: 5.62 } } ]

Please help me to correct this or give me some hint how to solve it.

Thanks in advance

Answer 1

You're running the second loop after the first loop is done, so the variables QUALITYNAME and rates_a1 have the values from the last iteration.

You can simply extract the object from the array and modify it in the first loop.

 var arr = [{ QUALITYNAME: "Berry Fancy", RATES: [{ "UNIT": "LB", "CURRENCY": "USD", "VALUE": 6.205240232694746 }] }, { QUALITYNAME: "Berry USDA", RATES: [{ "UNIT": "LB", "CURRENCY": "USD", "VALUE": 5.622770183585882 }] } ]; var value_a1 = null for (let i = 0; i < arr.length; i++) { var result = arr[i].RATES[0]; if (result) { result.VALUE = parseFloat(result.VALUE.toFixed(2)); } arr[i].RATES = result; } console.log(arr);

Answer 2

If I understand it correctly you're just trying to round all rates to two decimals, you can achieve that with a nested loop like:

var arr = [{
    QUALITYNAME: "Berry Fancy",
    RATES: [{
      "UNIT": "LB",
      "CURRENCY": "USD",
      "VALUE": 6.205240232694746
    }]
  },
  {
    QUALITYNAME: "Berry USDA",
    RATES: [{
      "UNIT": "LB",
      "CURRENCY": "USD",
      "VALUE": 5.622770183585882
    }]
  }
]

// Loop through each array item
arr.forEach((item) => { 
    // Loop through each rate inside the item
    item.RATES.forEach((rate) => {
        // Round to two decimals
        rate.VALUE = parseFloat(rate.VALUE.toFixed(2))
    });
})