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Need help to understand basic arithmetics in Java

 
raul saini
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Suppose we have this expression:



now i need to know how java performs this operation.
I know the precedence but still not able to figure out.

Please explain.
Thank You
 
fred rosenberger
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you should probably read something like this. operators all have a precedence - some get done before others, just like in math.

If i recall correctly, anything inside parens is done first, so we'd get

6*10/5*5+14/2-9+20

Then, mult/div come next, in order from left to right

60/5*5+14/2-9+20

60/5*5+14/2-9+20

12*5+14/2-9+20

60+14/2-9+20

60+7-9+20

then, addition and subtraction, in order from left to right

67-9+20
58+ 20
78



 
raul saini
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Thank you very much, I was performing multiple calculation at a time.
 
fred rosenberger
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well, you can, as long as you complete ALL operations of a given precedence before any others. I could have just as easily done this:

6*10/5*5+14/2-9+(10*2);

6*10/5*5+14/2-9+20; //take care of everything inside parens

60 + 7 - 9 + 20 // take care of all multiplication and division

78 // take care of all addition and subtraction.



 
Istvan Kovacs
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Note that with integer types, you can encounter issues due to losing data when performing calculations, which may make it seem that Java violates rules of arithmetics. For example:
(a / b * c) = (a * c / b) may not hold:

 
Campbell Ritchie
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That problem with integer arithmetic applies to most computer languages.
 
Rob Spoor
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With floating point calculations there can even be a difference between (a+b)+c and a+(b+c).
 
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