Create dynamically JSON keys in a JS loop

Question

I have this Javascript code with a JSON variable that works well.

var valuesJSON = {
    projects: {
        0: {value: 0, price: 0},
        1: {value: 0, price: 0},
        2: {value: 0, price: 0},
        3: {value: 0, price: 0},
        4: {value: 0, price: 0},
        5: {value: 0, price: 0},
        6: {value: 0, price: 0},
        7: {value: 0, price: 0},
    }
  }

I want to make it more scalable, so that it will read the number of entries from a constant. I tried the following but the for loop in the variable is not allowed. Any ideas?

const NUM_PROJECTS = 8
var valuesJSON = {
    projects: {
        for (var i=0; i < NUM_PROJECTS; i++) {
            i: {value: 0, price: 0},
        }
    }
  }

Answer 1

You need to add properties to projects using for loop. Bracket notation needs to used since variable is being used as key.

//Create object
var valuesJSON = {
   projects : {}
}

//Iterate and add properties
for (var i = 0; i < NUM_PROJECTS; i++) {
    valuesJSON.projects[i] = {
        value: 0,
        price: 0
    }
}

Answer 2

You could iterate with NUM_PROJECTS and generate new properties with the wanted result.

const NUM_PROJECTS = 8
var valuesJSON = { projects: {}};

for (var i = 0; i < NUM_PROJECTS; i++) {
    valuesJSON.projects[i] = { value: 0, price: 0 };
}

console.log(valuesJSON);