why equals methods printing false ?

[Raju Sri]

Hi ranchers,
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float f1= -0.0f;
float f2= +0.0f;
System.out.println(f1==f2);
Float obj1=new Float("-0.0");
Float obj2=new Float("+0.0");
System.out.println(obj1.equals(obj2));
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The above code prints "true false" as output.
Why obj1.equals(obj2) printing false eventhough -0.0 and +0.0 are equal ?
Raju

[Thomas De Vos]

Positive zero and negative zero compare equal; thus the result of the expression 0.0==-0.0 is true and the result of 0.0>-0.0 is false
In the first example a positive floating point zero and a negative
floating point zero compare equal according to the JLS. The result of
the expression 0.0 == -0.0 is true.
The equals method of the Float object compares the bit pattern. If both are identical the equals method returns true. The equals method uses the floatToIntBits method to determine the equality.
I have used the following code to test the above statement.

float f1= -0.0f;
float f2= +0.0f;
System.out.println(f1==f2);
Float obj1=new Float("-0.0");
Float obj2=new Float("+0.0");
        
System.out.println (Integer.toBinaryString(Float.floatToIntBit(obj1.floatValue())));
System.out.println (Integer.toBinaryString(Float.floatToIntBits(obj2.floatValue())));
System.out.println(obj1.equals(obj2));