Challenge #6 - Swap the values of two variables
Challenge #6 :
- Switch the values of two variables without using a third variable.
—hartnell
Challenge #6 - Swap the values of two variables
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» Challenge #6 - Swap the values of two variables
Summary:
without a third variable.
I did pm my code to you since there is practically only one useable way to do this.
The only way I know to do this is to use he Xor operator:
'Uses Xor to switch variables
'Richard Clark
'FreeBasic
'Public Domain
dim as integer a = 100, b = 456
print "A =";a, "B = ";b
'Use Xor to switch
a = a xor b
b = b xor a
a = a xor b
print "A =";a, "B = ";b
sleepRick, you can do it with simple math ;)
a = 1
b = 2
a = a + b (makes, a = 3 and b = 2)
b = a - b (makes, a = 3 and b = 1)
a = a - b (makes, a = 2 and b = 1)
Heh. I didn't think of that. Cool.
I think this works with any "complementary" functions, i.e. where you have one function that removes the effect of the other, e.g. +/-, xor/xor and i haven't tried, but i'm thinking functions like exp/log as well. So here's my contribution:
a = 5
b = 10
a = a * b (a = 50, b = 10)
b = a / b (a = 50, b = 5)
a = a / b (a = 10, b = 5)
These methods only work in theory because of limited space. I think only rickclark's method is a safe solution.
console.initialize
dim tmp
dim a
dim b
a = " Hello "
b = " World "
console.writeline(a & b)
tmp = b
b = a
a = tmp
console.writeline(a & b)
console.readline
console.terminateHi woad.
Unfortenately you did misunderstund this challeng. Idea is to change values of two variable with out using third variable wich in your case is tmp.
/forum/t-10796/challenge-6-swap-the-values-of-two-variables#post-
