Add property to all objects in array
you can use array.map,
and you should use Number() to convert props to numbers for adding:
var array = [ {'a': '12', 'b':'10'}, {'a': '20', 'b':'22'} ];
var r = array.map( x => {
x.c = Number(x.b) - Number(x.a);
return x
})
console.log(r)And, with the support of the spread operator, a more functional approach would be:
array.map(x => ({
...x,
c: Number(x.a) - Number(x.b)
}))
Use forEach function:
var array = [{ 'a': '12', 'b': '10' }, { 'a': '20', 'b': '22' }];
array.forEach(e => e.c = +e.b - +e.a);
console.log(JSON.stringify(array));