hi please explain the answer for the question given below Q5:Given two int variables initialized as follows: int a=63;// bit pattern ////// int b=4;// bit pattern 000100 what is the value of a&b. a).63 b).4 c).null d).0 answer:b

It's very easy to convert a decimal number to binary.... Just divide the given +ve decimal number by 2. Again divide the quotient with 2 repeatedly until you get quotient as zero. Then collect the remainders (which is either 1 or 0) and line them up in the reverse order i.e. right to left. Add zero's to fill up the remaining places. Example 1: 2)63(31 2)31(15 2)15(7 2)7(3 2)3(1 2)1(0 62 30 14 6 2 0 --- --- --- -- -- -- 1 1 1 1 1 1 so: 63 = 0011 1111 Example 2: 2)4(2 2)2(1 2)1(0 4 2 0 -- -- -- 0 0 1 so:4 = 0000 0100

Vishakha Ahuja
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Sorry about the apperance of division in the above reply, I tried some formatting to make it look like division (in maths text book) But, you see all my spaces have been collapsed....... Hope the above makes sense.

bala_chocos
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hi still u are confusing champak told me like 63=11111111 but vishak telling like this 63=00111111 Please explain help me

bala_chocos, vishak is right. 63 decimal = 00111111 binary. When you convert to binary, the same principles apply as in decimal numbers. Start with the decimal number 63. There is nothing in the hundredes position, a 6 in the tens position and a 3 in the ones position. So we get (6 * (10^1)) + (3 * (10^0)) = (6 * 10) + (3 * 1) = 63. The same logic applies for binary, but now instead of going by powers of 10 we go by powers of 2. Instead of having ones, tens, hundreds, thousands, etc. positions, we have ones, twos, fours, eights, sixteens, etc. positions. So, getting back to the decimal number 63. In binary we have: 0 in the sixty-fours position 1 in the thirty-twos position 1 in the sixteens position 1 in the eights position 1 in the fours position 1 in the twos position 1 in the ones position So: (1 * (2^5)) + (1 * (2^4)) + (1 * (2^3)) + (1 * (2^2)) + (1 * (2^1)) + (1 * (2^0)) = (1 * 32) + (1 * 16) + (1 * 8) + (1 * 4) + (1 * 2) + (1 * 1) = 63; 00111111 binary = 63 decimal Hope this helps. Stephanie

Thank you Vishakha and Stephanie for explaining how to convert decimal numbers into binary numbers so nicely .It has really cleared up by fundas. Thanks Ira ------------------