• 0 Posts
  • 13 Comments
Joined 11 months ago
cake
Cake day: August 16th, 2023

help-circle












  • activ8r@sh.itjust.workstoProgrammer Humor@lemmy.ml*Permanently Deleted*
    link
    fedilink
    arrow-up
    2
    arrow-down
    1
    ·
    edit-2
    9 months ago

    In JS a Boolean has 4 states.
    true
    false
    undefined (where the key is set to undefined)
    undefined (where the key doesn’t exist on the object)

    if (obj.value === true) {  
        console.log(1);
    } else if (obj.value === false) {
        console.log(2);
    } else if ("value" in obj) { // key "value" is in the obj, but it is set to undefined 
        console.log(3);
    } else { // key "value" is not in object
        console.log(4);
    }
    

    You’re welcome.