I need to understand the Conditional ternary statement

Question

So I tried to change the code below into a ternary operator, but it gave me and undefined result. Please can someone explain to me where I went wrong and how to deal with it appropriately. T for thanks.

const plantNeedsWater = function (day) {
  /*if (day === 'Wednesday'){
    return true;
  } else {
    return false;
  }*/
  (day === 'Wednesday') ? true : false
  return
}

console.log(plantNeedsWater('Tuesday'));

return day === 'Wednesday', you should put linting – EugenSunic Aug 25 '20 at 22:47 — EugenSunic, Aug 25 '20 at 22:47
@EugenSunic Post that as an answer. – Barmar Aug 25 '20 at 22:48 — Barmar, Aug 25 '20 at 22:48
@Barmar are you serious... – EugenSunic Aug 25 '20 at 22:48 — EugenSunic, Aug 25 '20 at 22:48
Putting `return` on the wrong line is just a typo. – Quentin Aug 25 '20 at 22:48 — Quentin, Aug 25 '20 at 22:48

Roko C. Buljan · Accepted Answer · 2020-08-25T23:11:45.623

0

A function with a simple plain return; returns undefined, not a primitive Boolean.

Also, you don't need a ternary operator, simply return your evaluation

const plantNeedsWater = function (day) {
  return day === 'Wednesday';
}

console.log(plantNeedsWater('Tuesday'));   // false
console.log(plantNeedsWater('Wednesday')); // true

or in an ES5 fashion using Arrow Function with implicit return:

const plantNeedsWater = (day) => day === 'Wednesday';

Otherwise, if you really must use the Conditional (ternary) Operator you could use it to return non-Boolean values:

const plantNeedsWater = function (day) {
  return day === 'Wednesday' ? "yes" : "no";
}

console.log(plantNeedsWater('Tuesday'));   // "no"
console.log(plantNeedsWater('Wednesday')); // "yes"

edited Aug 25 '20 at 23:11

answered Aug 25 '20 at 22:48

Roko C. Buljan

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Thank you for the quick response, you're right about that solution. Much appreciated. – nkadm Aug 25 '20 at 22:57
@nkadm You're welcome. It was really a typo... but hopefully you now got some more insight and solutions in your toolbox. – Roko C. Buljan Aug 25 '20 at 22:58

I need to understand the Conditional ternary statement

1 Answers1