JavaScript/28_Truthy_FalseyValue.js at main · TarunSharma-droid/JavaScript · GitHub

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/*
   Falsy value : false he man liya jata hai

   false , 0 , -0 ,BigInt 0n , ""(empty string " without space") , null , undefined , NaN

   Truthy values : true he man liya jata hai  : rest everything are considered as true

   like --> "0" (0 is written inside the string here) ,
            "false"
            [] (empty array)
            " " ( with space)
            {} (empty object)
            function(){} (empty function)

*/


const userEmail = "tarunsharma@gmail.com"

if(userEmail){
    console.log("Got the user email")

}
else {

    console.log("Dont have user email")
}


if ( "" ){ // does not run "" is considered false and if statement does not run false condition

    console.log("falsy value")
}


// To check the object is empty

const abc = {} //empty object

if ( Object.keys(abc).length === 0 ){

    console.log("the object is empty")
}
/* Object.keys(abc) --> this function will retun all the keys of the object in from of array.
   Since here object is empty so the key array will also be empty [].
   Now since the length of the empty array is 0 .
   So Object.keys(abc).length will retun 0.

*/