Testing if a list of integer is odd or even

Question

Trying to determine if my list of integer is made of odd or even numbers  my desired output is a list of true an or false   Can I perform the following operation on the list lst or do I need to create a loop  A is the output       List  lt int gt  lst   new List  lt int gt         A   IsOdd lst

User · Answer

There s at least 7 different ways to test if a number is odd or even  But  if you read through these benchmarks  you ll find that as TGH mentioned above  the modulus operation is the fastest   if  x   2    0                   even number         else                  odd number   Here are a few other methods  from the website       bitwise operation if   x  amp  1     0           even number else         odd number    bit shifting if    x  gt  gt  1   lt  lt  1     x           even number else          odd number    using native library System Math DivRem  long x   long 2  out outvalue   if   outvalue    0           even number else          odd number

User · Answer

region even and odd numbers         for  int x   0  x  lt   50  x   x   2                         int y   1              y   y   x              if  y  lt  50                                Console WriteLine  Odd number is       x        even number is       y      order by Asc                    Console ReadKey                              else                               Console WriteLine  Odd number is       x        even number is   0  order by Asc                    Console ReadKey                                        order by desc          for  int z   50  z  gt   0  z   z - 2                        int w   z              w   w - 1              if  w  gt  0                                Console WriteLine  odd number is      z        even number is      w      order by desc                    Console ReadKey                              else                               Console WriteLine  odd number is      z        even number is  0  order by desc                    Console ReadKey

User · Answer

Just use the modulus   loop through the list and run the following on each item  if num   2    0        is even   else       is odd     Alternatively if you want to know if all are even you can do something like this   bool allAreEven   lst All x   gt  x   2    0

User · Answer

--simple codes--           region odd   even numbers  order by desc            declaration of integer         int TotalCount   50          int loop           Console WriteLine   n---------Odd Numbers ------- n             for  loop   TotalCount  loop  gt   0  loop--                        if  loop   2    0                                Console WriteLine  Even numbers     0    loop                                    Console WriteLine   n---------Even Numbers ------- n             for  loop   TotalCount  loop  gt   0  loop--                        if  loop   2    0                                Console WriteLine  odd numbers     0    loop                                    Console ReadLine              endregion

User · Answer

You could try using Linq to project the list   var output   lst Select x   gt  x   2    0  ToList      This will return a new list of bools such that  1  2  3  4  5  will map to  false  true  false  true  false

[c#] Testing if a list of integer is odd or even

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