javascript - Function returns undefined with ternary operator - Stack Overflow

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I am trying to wrap my head around the isBreadwinner function. Why does not true pass into the (**) function. Why is Earning member:undefined

<script>
    "use strict"

    //creating a user object 
    let user = {
        name : "Stackoverflow Developer",
        age : 23
    };

    // appending properties to the user object
    user.location = "NYC";
    user["occupation"] = "JavaScript Developer";
    user["salary"] = 10;

    //(**)
    let isBreadwinner = () => {
        (user.salary) ? true : false;
    };

    console.log("asd" + isBreadwinner());
    user["Earning member"] = isBreadwinner();

    // printing the object
    console.dir("User dir object" + JSON.stringify(user));
    console.dir(user); //Earning member:undefined
</script>

I am trying to wrap my head around the isBreadwinner function. Why does not true pass into the (**) function. Why is Earning member:undefined

<script>
    "use strict"

    //creating a user object 
    let user = {
        name : "Stackoverflow Developer",
        age : 23
    };

    // appending properties to the user object
    user.location = "NYC";
    user["occupation"] = "JavaScript Developer";
    user["salary"] = 10;

    //(**)
    let isBreadwinner = () => {
        (user.salary) ? true : false;
    };

    console.log("asd" + isBreadwinner());
    user["Earning member"] = isBreadwinner();

    // printing the object
    console.dir("User dir object" + JSON.stringify(user));
    console.dir(user); //Earning member:undefined
</script>

• javascript
• function
• undefined

Share Improve this question Follow edited Aug 6, 2017 at 5:22 lft93ryt asked Aug 6, 2017 at 5:13 lft93rytlft93ryt 1,01611 gold badge1717 silver badges3434 bronze badges

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2 Answers 2

Sorted by: Reset to default 5

You're missing the return in your isBreadWinner function.

let isBreadwinner = function() {
    return (user.salary) ? true : false;
};

If you want to skip using a return then you might want to use an ES6 arrow function which has implicit returns if everything is declared on one line without a block, {}.

let isBreadwinner = () => (user.salary) ? true : false;

you may write the function like this

let isBreadwinner = () => (user.salary) ? true : false;

or just add return to your function

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