Geek Answers Handbook

Selection from left to right

In C #, is it guaranteed that expressions are evaluated from left to right?

For example:

myClass = GetClass();  
if (myClass == null || myClass.Property > 0)  
    continue;

Are there any languages ​​that don't match?

+5
source share
9 answers

In fact, you are referring to a language function called "logical expression short circuit":

This means the following: when the result of a logical expression can no longer change, for example. when it is clear that the expression will be evaluated as “true” or “false”, regardless of whether the remaining parts of the expression will be evaluated.

, #, Java JavaScript , ( ).

, MyClass null:

  • MyClass == null false
  • "", ,
  • myClass.Property > 0

MyClass null:

  • MyClass == null true
  • "", ,
  • , .

, . VB , "myClass.Property > 0" , MyClass ( "Nothing" VB).

+14

7.11 # 3.0:

x || y x | y, , y , x .

, .

- . VB.NET OrElse AndAlso, , Or And .

+5

:

-

sprintf (buf, "% s% s", func1 (& var), func2 (& var));

var, ( C, , ), func1() func2() ( , ( ) .

+2

, (||) short-circuiting, , .

0

, ?

100%, , # ( , , .net). , .

# (& & &). , , .

0

/ , Ada, Visual Basic Pascal, . , " " " " Ada.

0

Python or and.

0

Java Haskell && || .

, Haskell ( , ), Java # .

0

- , , - . , C (ANSI, ISO, C99) . NULL ... , . - .

0

More articles:


All Articles