What is a magic number?

Question

I want the definition of a magic number.I am a class 10 student in the ICSE board.

This is in regard to computer programming.

Answer 1

example:19
1+9=10
1+0=1
a magic no. is one whose digits when kept on added according to the above pattern gives answer as 1.
Other magic no.s are:28,37,46,etc

Answer 2

1. The atomic number of an extra stable strongly bound atomic nucleus: 2, 8, 20, 28, 50, 82 or 126 are called magic numbers

2. In sports, a magic number is a number used to indicate how close a front-running team is to clinching a season title. It represents the total of additional wins by the front-running team or additional losses by the rival team after which it is mathematically impossible for the rival team to capture the title in the remaining games.

3. In nuclear physics, a magic number is a number of nucleons such that they are arranged into complete shells within the atomic nucleus. The seven known magic numbers as of 2005 are:

2, 8, 20, 28, 50, 82, 126.


Hope it gives you a good knowledge!

Answer 3

its got no short ans. but me try , like for Source-code there are some non-obvious constant whose value is significant to the operation of a program and that is inserted inconspicuously in-line rather than expanded in by a symbol set by a commented #define .
another is as in an algorithm A number that encodes critical information used in some opaque way. like numbers used in hash or CRC functions, or the coefficients in a linear congruential generator
also in Algorithms An input that leads to a computational boundary condition, where algorithm behavior becomes discontinuous .

thre is also The magic number, on the other hand, is 7±2. See The magical number seven, plus or minus two: some limits on our capacity for processing information by George Miller, in the Psychological Review 63:81-97 (1956).

Answer 4

Its a number used for a specific purpose. A lot of times I'll see comments in code saying NO MAGIC NUMBERS because it wasn't immediately obvious what the code was doing. It is always best to use #defines. Personally I don't use the term very often. This bootloader I was using would jump to address 2000 on the flash and the image didn't start with the "MAGIC NUMBER" it would say "BAD MAGIC NUMBER" and I'd know I didn't program the flash correctly.

Answer 5

Numbers are not "magic". They are just numbers.
However, the one we consider as the most "beautiful" number is PHI, equal to 1.618, called also the golden proportion.
It comes from the resolution of the equation
a / b = b / c, where c = a + b.
It also comes from the Fibonaci sequence (1, 1, 2, 3, 5, 8, 13, 21...)
The quotient of two consecutive numbers approaches 1.618 as you go further in the sequence. Check it with you calculator!

Answer 6

"A man and a woman had a little baby, yes they did, they had threeee in the family thats a magic number"

But seriously in programming "a magic number is a special constant used for some specific purpose. It is called magic because it is hardcoded in and its value or presence is inexplicable without some additional knowledge."

Answer 7

What you are asking no one can tell, because you must have heard it in a problem "Write A Program..." type. And such a name can be given to any kind of number. For example it can be:
1. A number sum of whose digits can be equal to itself
2. A number which repeats itself... etc

Answer 8

I never heard of a magic number. I assume it cound be any number your lucky enough to win at lottery. Thank the lord that he gave you one more day to live.

Answer 9

Three is a magic number. My favorite number in nine - three threes!

Answer 10

Mine is 21