简化 Javascript 中的嵌套三元

Question

I have the following code:

return this.condition1
        ? condition2
          ? true
          : false
        : false

Is there a way to write this without using true false ?

Answer 1

Yes, you can simplify that; you don't need any ternary operators:

return this.condition1 && condition2;

Performing a test in order to choose either true or false is redundant. You can use !! to turn a "truthy" value into a boolean value, and if the test expressions already provide boolean values (such as > or < comparisons) then you've already got the values you need.

Answer 2

return this.condition1 && condition2;

should be sufficient for using in if and other conditions. Note that it's not strictly equivalent javascript to your code.

To be certain to return true or false (as the primitive boolean values), you need to coerce this as a boolean like this :

return !!(this.condition1 && condition2);

(this is really for the sake of exactitude, and I would style recommend the first simpler version in most cases, though).