Boolean check

[Chitra AP]

public class CompareTest {
public static void main(String[] args) {
boolean b1 = false;
int i1 = 2;
int i2 = 3;
 
if (b1 = i1 == i2) {
System.out.println("true");
} else {
System.out.println("false");
}
 
}
}

I understand the expression (b1 = i1 == i2) gives you false here.
So, if (false) System.out.println("true") and it should print true, right??
But it prints false, why??? :roll:

Thanks

[vidya sagar]

Hi Chitra

Equals operator has the higher priority than assignment operator
so first equals operation takes place.In this case,it evaluates to false.Second step false is assign to b1.Finally if any boolean assignment
takes place in if condition, assigning value is the result of if condition.
So it prints false.

Hope ur clear

[Barry Gaunt]

Chitra, please read my post in this thread of yours. If you do not change your displayed name, your JavaRanch membership will be suspended, and you will not be able post.
Thanks
-Barry

(NR close this account: Member # 99544)

[Fes D Gaur]

If you replace the statement:

if (b1 = i1 == i2)

with

if (false)

then it will still print false as the output. The thing to understand here is that the if condition looks for:

if(true)
//then print this
else
//print this.

In your example code the condition was false so it will print the output of the else condition.

[usha prithvi]

Hi,

In the program written by chitra as......
public class CompareTest {public static void main(String[] args) {boolean b1 = false;int i1 = 2;int i2 = 3;
if (b1 = i1 == i2) {
System.out.println("true");}
else {
System.out.println("false");}
}
}

y should the expression be (b1 = i1 == i2). and y not (b1 == i1 == i2)?

thankz for ur reply

[Timmy Marks]

(b1 == i1 == i2) is illegal. when is a boolean == an int ?

in the expression (b1 = i1 == i2), b1 gets assigned the value of (i1 == i2), so true if i1 and i2 are equal. It would be clearer if it were retyped so :

int i1 = 2, i2 = 3;
boolean b1;
if (i1 == i2){
  b1 = true;
} else {
  b1 = false;
}
if (b1){
  System.out.println("true");
} else {
  System.out.println("false");
}

but that is much too long. Better is

boolean b1 = (i1 == i2);

instead of the first if block. Such constructs as

if (b1 = i1 == i2) {
}

are more commonly seen in C, where some people are of the opinion that an extra hour spent reading their code is worth the extra two minutes they would spend typing the extra characters.