最新消息:Welcome to the puzzle paradise for programmers! Here, a well-designed puzzle awaits you. From code logic puzzles to algorithmic challenges, each level is closely centered on the programmer's expertise and skills. Whether you're a novice programmer or an experienced tech guru, you'll find your own challenges on this site. In the process of solving puzzles, you can not only exercise your thinking skills, but also deepen your understanding and application of programming knowledge. Come to start this puzzle journey full of wisdom and challenges, with many programmers to compete with each other and show your programming wisdom! Translated with DeepL.com (free version)

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

matteradmin7PV0评论

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';
    }
  }

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';
    }
  }
Share Improve this question edited Jun 14, 2017 at 7:14 RNA asked Jun 14, 2017 at 6:47 RNARNA 1,0913 gold badges20 silver badges43 bronze badges 1
  • 5 yes, name could be n :p let name = app.short_name || app.name || 'Untitled'; – Jaromanda X Commented Jun 14, 2017 at 6:48
Add a ment  | 

3 Answers 3

Reset to default 9

Use Logical OR (||) operator

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

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

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 bee 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.

Articles related to this article

Post a comment

comment list (0)

  1. No comments so far