Question on If condition, How this works

Question

int a=7,b=1;

Question 1: Value of a is 8
Question 2: Value of a is 1

Question 1:

if(a=8)
cout<< a;

Question 2:

if(a=8 || b==5)
cout<< a<<b;

Answer 1

The single '=' means assignment not comparison. The If statement expects a boolean value.

for question 1 the if statement after assignment becomes

if(a)
cout<<a;

since a is not 0 or NULL it will be evaluated as true and the if statement executes and 8 is printed out ( since a is assigned 8 )

for question 2 after assignment the if statement becomes

if(a || b==5)
cout<<a<<b;

here again since a is not 0 or NULL the statement becomes true. Note that the second condition b==5 is not checked since the first condition is true ( in an OR statement if the first condition is true, the second condition is skipped)

If you want the correct comparison use '==' instead of '='