In the "&&" check, will the second part fail if the first part is false?

Question

Programming

In the "&&" check, will the second part fail if the first part is false?
if(a ==1 && b == 2)
If a is false, then b will not be executed?

Answer 1

Depends on the programming language. For example, VisualBasic has two operators, And and AndAlso. And always evaluates both arguments, AndAlso evaluates the second argument only if the first one is true.

Answer 2

Naturally

Answer 3

Yes. Have you ever seen the design?
if(Obj != null && Obj.field != null) { }

Answer 4

Yes. In C+, this is the so-called "short scheme". If the result of the first part allows you to unambiguously obtain the result of the entire expression, the rest of the expression is not calculated. The situation is the same with the || operator. Rumor has it that if you override these operators, then the "shortcut" won't work.

Answer 5

Here is a general description of the principle and how it works in different languages: Short-circuit evaluation .