I have an object that I'm using to keep track of which checkboxes have been checked on a UI.

It looks something like this:

      checked: { key1: false, key2: false, key3: false, key4: false, key5: false, key6: false, key7: false, key8: false, key9: false, key10: false },

I need to be able iterate through this object and set certain values to true/false, depending on the behavior the user wants from the UI.

I have two questions:

1. Is there a more elegant way to instantiate this?

2. How would I do this using the Object.entries method?

I'd like to do something like this, but it doesn't work:

let obj = {k1: false, k2: false, k3: false}

Object.entries(obj).forEach(([key, value]) => {
    obj.value = true;
  console.log(`${key} ${value}`);

});

Thank you!

I have an object that I'm using to keep track of which checkboxes have been checked on a UI.

It looks something like this:

      checked: { key1: false, key2: false, key3: false, key4: false, key5: false, key6: false, key7: false, key8: false, key9: false, key10: false },

I need to be able iterate through this object and set certain values to true/false, depending on the behavior the user wants from the UI.

I have two questions:

1. Is there a more elegant way to instantiate this?

2. How would I do this using the Object.entries method?

I'd like to do something like this, but it doesn't work:

let obj = {k1: false, k2: false, k3: false}

Object.entries(obj).forEach(([key, value]) => {
    obj.value = true;
  console.log(`${key} ${value}`);

});

Thank you!

• javascript
• arrays
• reactjs
• mapping
• jsx

• What do you mean by set values to true/false depending on behavior? And it's probably more extensible to store key/value pairs in an array or a map than in distinct properties. – Jawi Commented Feb 18, 2020 at 17:49
• 1 thanks for your response. I'm working on a "select none" option for the checkboxes on a page. If a user clicks on "select none", I need to set all the items in the object to false. If a user clicks "select all", I need to set them all to true. If a user selects some of them, I need to update the boolean values of the key/value pairs in the object to reflect which are selected and which aren't. I've updated my question with my attempt at using Object.entries the way I need it to work. – helloWorld Commented Feb 18, 2020 at 17:51
• what didn't work on your example? – Tom Mendelson Commented Feb 18, 2020 at 17:55
• @TomMendelson the result of console.log prints out all the key/value pairs with a false value – helloWorld Commented Feb 18, 2020 at 17:56

2 Answers 2

If you need to set all the values in the object to true, you can do something like this

Object.keys(obj).forEach(key => obj[key] = true);

Object.keys will return all the keys in that object in an array. By looping over that array and then using obj[key] we can access each key of the object and set it to true

To answer your questions -

1. This is a pretty good way to store multiple checked booleans, as you can access them using object destructuring like const { key1, key2, ... } = checked which, IMHO makes the code more readable.

2. Try -

Object.entries(obj).forEach([key, value] => {
  // Set obj key/value
  obj[key] = true  // or use value here
})

Refer -

https://developer.mozilla/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries