C++ code ( 6 )

Question

What is the output of this code？
intx( int &a, int &b){
a=3;
b=4;
return a + b;
}
int main(){
int a=2;
int b=7;
int c=x(a, a);
cout<<a<<b<<c;
How to calculate it？

Answer 1

Hi Alice... The answer is 478.

Here is a breakdown of each variable:

Variable {a} initializes as 2. The pointer to this variable is then passed to the following method:

x(a, a);

NOTE: When {b} is assigned the value 4, both {a} and {b} are set to the value 4. This is because both arguments were passed as pointer references to the original variable {a}. The return value is the sum of a + b, which should be 4 + 4, or 8.

So, now, {a} in the main() function is 4. The return value of x(a, a) was assigned to variable {c}, which is 8. The variable {b} has not changed and is still 7.

Therefore, the final value is:

a=4, b=7, c=8

I hope this makes sense.

Answer 2

@Freddy: Indeed... this code, as well as, most code in SL challenges, are great models to follow for those seeking to be chronically unemployed. 🤣

Answer 3

challenge question, right?

Answer 4

@David Caroll Wow...I'm speechless！Now I know how to calculate it，thanks for sharing your knowledge😄

Answer 5

Nice explanation David :)

Outside of this lovely acedemical discussion, I would like to add that I would advise *not* to use a construction like this in real code. To put it mildly: it doesn't approve readability and thus can lead to nasty side effects and bugs.
And in this case the good news is that there *is* a predicable outcome, sometimes (especially when you use macros) the outcome isn't even predictable or even defined in the standard and thus compiler specific... You might want to avoid code like that :)

Answer 6

there are many programmer wow nice am new in this field