CODEWITHSUNDEEP
javascript
RNA
RNA

Reputation: 1071

javascript, can this code (nested IF statement) be shorter?

I think below code can be simpleer somehow. Can this code be optimized?

let name = app.short_name;
  if (name === undefined) {
    name = app.name;
    if (name === undefined) {
      name = 'Untitled';
    }
  }

Upvotes: 2

Views: 104

Answers (3)

hol
hol

Reputation: 8423

Javascript will assign what it considers true. If you concat with || (OR) then each value is checked for true until a true value is found and is assigned.

There are a number of values that become false for example:

  • undefined
  • 0
  • null
  • '' (empty String)
  • NaN

This is why you could write

let name = app.short_name || app.name || 'Untitled';

because if app.short_name has a value it will be true rather than false and it is assigned. But if it is undefined it will be considered false and app.name will be checked if it is true. If it is undefined it will be again considered false and so finally 'Untitled' is considered and deemed true and assigned to name. Might want to look at this link.

Upvotes: 4

Nina Scholz
Nina Scholz

Reputation: 386610

You could use a default chain with logical OR || in a short-circuit evaluation.

let name = app.short_name || app.name || 'Untitled';

But I suggest to use a variable name different of name, because it is usually a property of window

Upvotes: 8

Rayon
Rayon

Reputation: 36599

Use Logical OR (||) operator

let name = app.short_name || app.name || 'Untitled';

Upvotes: 9

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