What is the OR operator in an IF statement

Question

In C   how do I specify OR   if this OR that   do the other thing    I couldn t find it in the help   Update   My code is   if  title     User greeting      User name    do stuff    and my error is      Error  1   Operator      cannot be applied to operands of type  bool  and  string  C  Documents and Settings Sky View Barns My Documents Visual Studio 2005 Projects FOL Ministry FOL Ministry Downloader cs   63  21  FOL Ministry

User · Accepted Answer

is the conditional OR operator in C   You probably had a hard time finding it because it s difficult to search for something whose name you don t know   Next time try doing a Google search for  C  Operators  and look at the logical operators   Here is a list of C  operators      My code is   if  title     User greeting      User name    do stuff         and my error is       Error 1 Operator      cannot be   applied to operands of type  bool  and    string  C  Documents and Settings Sky   View Barns My Documents Visual Studio   2005 Projects FOL Ministry FOL   Ministry Downloader cs 63 21 FOL   Ministry   You need to do this instead   if  title     User greeting     title     User name    do stuff     The OR operator evaluates the expressions on both sides the same way   In your example  you are operating on the expression title     User greeting   a bool  and the expression  User name   a string    These can t be combined directly without a cast or conversion  which is why you re getting the error   In addition  it is worth noting that the    operator uses  short-circuit evaluation    This means that if the first expression evaluates to true  the second expression is not evaluated because it doesn t have to be - the end result will always be true   Sometimes you can take advantage of this during optimization   One last quick note - I often write my conditionals with nested parentheses like this   if   title     User greeting       title     User name     do stuff     This way I can control precedence and don t have to worry about the order of operations   It s probably overkill here  but it s especially useful when the logic gets complicated

User · Answer

you need  if  title     User greeting     title     User name    do stuff

User · Answer

In the format for if   if  this OR that     this and that are expression not values  title     aaaaa  is a valid expression  Also OR is not a valid construct in C   you have to use

User · Answer

The OR operator is a double pipe        So it looks like   if  this    that         do the other thing     EDIT   The reason that your updated attempt isn t working is because the logical operators must separate valid C  expressions   Expressions have operands and operators and operators have an order of precedence     In your case  the    operator is evaluated first   This means your expression is being evaluated as  title     User greeting       User name   The    gets evaluated next   Since    requires each operand to be a boolean expression  it fails  because your operands are strings   Using two separate boolean expressions will ensure that your    operator will work properly   title     User greeting     title     User name

User · Answer

See C  Operators for C  operators including OR which is

User · Answer

The conditional or operator is      if  expr1    expr2   do stuff   if  title     User greeting     title     User name    do stuff    The conditional  the OR  and it s parts are boolean expressions   MSDN lists the C  operators in precedence order here http   msdn microsoft com en-us library 6a71f45d aspx   And the MSDN page for boolean expressions is http   msdn microsoft com en-us library dya2szfk aspx    If you are just starting to learn programming  you should read up on Conditional Statements from an introductory text or tutorial  This one seems to cover most of the basics  http   www functionx com csharp Lesson10 htm

User · Answer

Just for completeness  the    and  amp  amp  are the conditional version of the   and  amp  operators   A reference to the ECMA C  Language specification is here   From the specification      3 The operation x    y corresponds to   the operation x   y  except that y is   evaluated only if x is false    In the   version both sides are evaluated   The conditional version short circuits evaluation and so allows for code like   if  x    null    x Value    5         Do something    Or  no pun intended  using your example   if  title     User greeting     title     User name            do stuff

User · Answer

OR is used as        if expr1    expr2         do something

User · Answer

Or is     And is  amp  amp   Update for changed question   You need to specify what you are comparing against in each logical section of the if statement   if  title     User greeting     title     User name             do stuff

User · Answer

The reason this is wrong   if  title     User greeting      User name    do stuff     is because what that s saying is  If title equals the string  User greeting   or just  User name    not if title equals the string  User name     The part after your or would be like writing   if   User name     which c  doesn t know what to do with   It can t figure out how to get a boolean out of  User name

[c#] What is the OR operator in an IF statement

Examples related to c#

Examples related to conditional-operator