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--- syntax:functions:if [2016/06/08 00:14] – dmitry
+++ syntax:functions:if [2021/08/16 02:42] (current) – [Examples] craigt
@@ Line 1: / Line 1: @@
-====== If(condition, expression1, expression2) ======
+====== If(condition, when_true, when_false) ======
+Category:  Logical function
-Returns the result of //expression1// if //condition// is true. Otherwise returns the result of //expression2//.
+\\
+=====Description=====
+This function evaluates //condition// and returns the //when_true// value if the condition is true, or //when_false// if not.
-^  Example  ^  Result  ^
+\\
-| if( 2 + 2 = 4, 'Makes sense', 'Nonsense' )  | Makes sense  |
+=====Arguments=====
-| if( 2 + 1 = 4, 'Makes sense', 'Nonsense' )  | Nonsense  |
+^Argument^Type^Description^
+|condition|Expression|This is an expression or "test" that evaluates to either TRUE or FALSE.|
+|when_true|Expression|If the //condition// evaluates to TRUE, this value is returned.|
+|when_false|Expression|If the //condition// evaluates to FALSE, this value is returned.|
+**Return value type:** Text, Number, Boolean (the value types used for //when_true// and //when_false//)
+\\
+=====Remarks=====
+To return a Boolean TRUE or FALSE value, use the [[syntax:functions:true|True()]] and [[syntax:functions:false|False()]] functions.
+If() functions can be nested to provide decisions based on more than a single test, and return a value from more than just two choices.  See examples below.
+Both //when_true// and //when_false// values are always evaluated, even if only one of them is returned.
+\\
+=====Examples=====
+  if(2+2=4, "Yes it does", "No it doesn't") //Returns "Yes it does"
+  if("This" = "That", 1, 0) //Returns 0  (Returns a numeric zero.)
+  if(rem(4,2)=0,"Number is even","Number is odd") //Returns "Number is even"  (Using a function in the condition.)
+  if({MyVal}+6=8,"Is 2","Is not 2") //Returns "Is not 2"  (Where "MyVal" = 3, parameters are supported.)
+\\
+====Nested if()s====
+Another "level" of logic can be introduced by using a nested if() for the outer if()'s TRUE and/or FALSE value(s).  This becomes the equivalent of an "elseif" branch.
+  if( [Field1)>10, "More than 10", if( [Field1]>0, "More than 0, less than 10", "Less than 0" ) )
+If [Field1] is greater than 10, the condition is evaluated to TRUE and the //when_true// value ("More than 10") is returned.  However, if the condition is evaluated to FALSE, the //when_false// "value" is another if() test, which is evaluated.  In this case, if [Field1] is greater than 0, "More than 0" is returned, otherwise "Less than 0" is.
+Nested if()s can be used for the //condition//, the //when_true//, and/or the //when_false// values.
+\\
+===== See also =====
+  * [[syntax:functions:ifempty|IfEmpty(expression1, expression2)]]
+  * [[syntax:functions:iferror|IfError(expression1, expression2)]]
+  * [[syntax:functions:false|False()]]
+  * [[syntax:functions:true|True()]]