如何在 FETCH PUT API 中将 json 主体作为字符串传递给 React js

Question

how to pass json body as String in FETCH PUT API in react js? I am trying to 20 addition to the Balance like this Balance: details[0].Balance.toString() + 20 which didnt work. i want to hve it as string altogether

Any help would be greatly appreciated. please

Below Sample code:

fetch(memberput, {
  method: 'PUT',
  headers: curHeaders,
  body: JSON.stringify({
  ID:details[0].ID.toString(),
  Balance: details[0].Balance.toString() + 20
  })
  })
  .then(function(response){
    console.log('Final ', response.json());
  })

Expectedoutput: If currentbalance is 30, it should give me 30+20 = 50

Actual output: If currentbalance is 30, its giving me 3020 now.

Answer 1

String + string = concatenate strings

String + number = concatenate string and number

Number + number = sum of the number

What you should do is something like

Const balance = (Number(details[0].Balance) + 20).toString();

First, you need to ensure that the balance is a number, then add the 20 or the variable you want, and then convert it to a string. Then you can use that balance constant to send the data.