So I have been racking my brain why this doesn't work, I am sure that I am over thinking it . So the main thing I am trying is to create a JavaScript function “myGame” which takes game Object and returns some custom message so that when the prompt is left undefined its should say please provide your fav game

My attempt;

let game = prompt('What is your fav game');
function myGame(game){
    if(game === undefined){
        console.log('Pls provide your fav game');
    }else{
        console.log(`My fav game is ${game}`)
    }
}
myGame(game);

CodePudding user response：

You can directly use like this:

if(prompt('What is your fav game')){
  console.log(`My fav game is ${game}`)
}else{
  console.log('Pls provide your fav game');  
}

If user cancels the prompt, it goes to else block. Alternatively, use if (!prompt()){} to better implement it checks (user sets the value):

if(!prompt('What is your fav game')){
  console.log('Pls provide your fav game');        
}else{
  console.log(`My fav game is ${game}`)
}

CodePudding user response：

From the prompt() docs:

Return value
A string containing the text entered by the user, or null.

So you'll need to check for null, not undefined.

If you press 'ok' right away, the value will be an empty string (''), so use !game to check for all false values

let game = prompt('What is your fav game');

function myGame(game){
    if (!game){
        console.log('Pls provide your fav game');
    } else{
        console.log(`My fav game is ${game}`)
    }
}
myGame(game);