My issue lies in the subtraction of a quantity by using Object X from Array 1 and Object Y from Array 2

Question

My issue lies in the subtraction of a quantity by using Object X from Array 1 and Object Y from Array 2

I am facing an issue with the function I'm using. It seems that when I attempt to do subtraction, both arrays are getting subtracted instead of just one.

Here are the variables:

let data1 = [
  { ProductTotalId: 30, ProductId: 30, Quantity: 50 },
  { ProductTotalId: 31, ProductId: 29, Quantity: 20 },
  { ProductTotalId: 32, ProductId: 28, Quantity: 30 },
  { ProductTotalId: 33, ProductId: 27, Quantity: 30 },
];

let Remove = [
  { ProductTotalId: 30, ProductId: 30, Quantity: 2 },
  { ProductTotalId: 30, ProductId: 30, Quantity: 10 },
  { ProductTotalId: 31, ProductId: 29, Quantity: 3 },
  { ProductTotalId: 32, ProductId: 28, Quantity: 12 },
  { ProductTotalId: 32, ProductId: 28, Quantity: 2 },
  { ProductTotalId: 33, ProductId: 27, Quantity: 11 },
  { ProductTotalId: 33, ProductId: 27, Quantity: 5 },
]
let data2

This is the function being used:

data2 = data1;
for (let value of data2) {
  for (let data of Remove) {
    if (value.ProductId === data.ProductId) {
      value.Quantity = value.Quantity - data.Quantity;
    }
  }

}
console.log(data1);
console.log(data2);

The problem here is that 'data1' is equal to 'data2' with Quantity Subtracted. What I actually need is for 'data2' to be subtracted without any changes to 'data1'.

Link to Stackblitz: https://stackblitz.com/edit/typescript-u8mzii

Thank you for your attention.

arrays typescript

Answer 1

Answer №1

Creating a reference for object by assigning data1 to data2 does not make a copy of the object <code>data1

. Any changes made to the reference data2 will also affect the object referenced by data1 (which is the same object).

To actually create a copy of the object, you can use the following method:

data2 = JSON.parse(JSON.stringify(data1));

Check out the DEMO here

Answer 2

Creating a reference for object by assigning data1 to data2 does not make a copy of the object <code>data1

. Any changes made to the reference data2 will also affect the object referenced by data1 (which is the same object).

To actually create a copy of the object, you can use the following method:

data2 = JSON.parse(JSON.stringify(data1));

Check out the DEMO here

Answer 3

Answer №2

The issue lies within the data structure you are using.

When you write data2 = data1;, it simply assigns a reference to the same array, not creating a new one.

For two separate arrays, you need to create a new array and populate it with the contents of the first array.

To achieve this, use the following code:

const data2 = Object.assign([], data1);

This will give you a duplicated copy of the original array.

Answer 4

The issue lies within the data structure you are using.

When you write data2 = data1;, it simply assigns a reference to the same array, not creating a new one.

For two separate arrays, you need to create a new array and populate it with the contents of the first array.

To achieve this, use the following code:

const data2 = Object.assign([], data1);

This will give you a duplicated copy of the original array.

Answer 5

Answer №3

To prevent any alterations in data2 from affecting data1, it is essential to duplicate data1 as data2. The method outlined below demonstrates how you can achieve this:

let data2 = JSON.parse(JSON.stringify(data1))

By first converting (JSON stringify) data1, and then parsing the result into data2, you ensure that they are identical but not the same.

Answer 6

To prevent any alterations in data2 from affecting data1, it is essential to duplicate data1 as data2. The method outlined below demonstrates how you can achieve this:

let data2 = JSON.parse(JSON.stringify(data1))

By first converting (JSON stringify) data1, and then parsing the result into data2, you ensure that they are identical but not the same.

My issue lies in the subtraction of a quantity by using Object X from Array 1 and Object Y from Array 2

Answer №1

Answer №2

Answer №3

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