Difference between revisions of "QVAL"

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(Created page with "QVAL is used to test if an arguement is true or false in a single line of code. <QVAL <EVAL <LOCAL.A>+1> < <LOCAL.B>? SYSMESSAGE LOCAL.A IS SMALLER:SYSMESSAGE LOCAL.B IS S...")
 
 
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QVAL is used to test if an arguement is true or false in a single line of code.
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==The first QVAL Syntax==
  
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<QVAL <EVAL <LOCAL.A>+1> < <LOCAL.B>?   SYSMESSAGE LOCAL.A IS SMALLER:SYSMESSAGE LOCAL.B IS SMALLER>
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<QVAL CONDITION ? TRUE : FALSE>
  
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In the above statement is we say that local.a = 3 and local.b = 5
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QVAL is a simple form of the IF-ELSE structure. It is used to test if an argument is true or false in a single line of code.
  
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Then local.a+1 = 4
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For example, this:
  
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4 being less that 5 means that the argument will return as true and so the first output in the true:false condition will be given
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IF (<EVAL <LOCAL.A>+1> < <LOCAL.B>)
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    SYSMESSAGE A+1 is smaller than B
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ELSE
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    SYSMESSAGE A+1 is greater than or equal to B
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ENDIF
  
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If local.a = 5 and local.b = 5
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...is the same as:
  
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Then local.a+1 = 6
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<QVAL <EVAL <LOCAL.A>+1> < <LOCAL.B> ? SYSMESSAGE A+1 is smaller than B:SYSMESSAGE A+1 is greater than or equal to B>
  
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In these circumstances the argument will return as false and so the condition after : being the false output will be given.
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In the above statement, if we say that local.a=3 and local.b=5, then local.a+1=4
  
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The argument does not have to be greater than or less than, it can also be equal to or even if a specific indicator such as a tag or defname just exists.
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Since 4 is less that 5, the condition is true, and so the first output (before the : sign) in the true:false condition will be executed
  
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If local.a=5 and local.b=5, then local.a+1=6
  
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Your argument must always be ended with a ?
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Since 6 is not less than 5, the condition will return as false and the second output (after the : sign) in the true:false result will be executed.
  
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Must always have 2 possible outputs TRUE:FALSE
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Your "if condition" is separated from the results by the ? character.  The true and false results are separated by the : character (which is mandatory, even if you dont want anything to happen in one of the cases.)
  
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And is closed with a >
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Be careful if the true:false conditions also require you to use "greater than"  It is easy to inadvertently close an argument too soon with a misplaced > after the ? or : in a QVAL argument. You should use always Less than ( < ) or Less or Equal ( <= )
  
  
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Be careful if the true:false conditions also require you to use "greater than"  It is easy to inadvertently close an argument too soon with a misplaced > after the ? or : in a QVAL argument.
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==The second QVAL Syntax==
  
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QVAL(VALUE1,VALUE2,LESSTHAN,EQUAL,GREATERTHAN)
  
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This form of the QVAL statement is useful when comparing two values.
  
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For example:
  
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QVAL(test1,test2,res1,res2,res3) in addition to current <QVAL?:> variant. It is useful if dealing with numbers without many IF-s.
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<eval qval(<VAR.X>,<VAR.Y>,<VAR.ONE>,<VAR.TWO>,<VAR.THREE>)>
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Sample <eval qval(<VAR.X>,<VAR.Y>,<VAR.ONE>,<VAR.TWO>,<VAR.THREE>)> will return <VAR.ONE> if <VAR.X> < <VAR.Y>, <VAR.TWO> if they are equal, and <VAR.THREE> if the it is greater. If some of the arguments are omited like qval(1,2,,3) it will default to zero
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...will return <VAR.ONE> if X is less than Y, <VAR.TWO> if they are equal, and <VAR.THREE> if X greater than Y. If some of the arguments are omited like qval(1,2,,3) it will default to zero.

Latest revision as of 20:44, 28 November 2013

The first QVAL Syntax

<QVAL CONDITION ? TRUE : FALSE>

QVAL is a simple form of the IF-ELSE structure. It is used to test if an argument is true or false in a single line of code.

For example, this: 

IF (<EVAL <LOCAL.A>+1> < <LOCAL.B>)
   SYSMESSAGE A+1 is smaller than B
ELSE
   SYSMESSAGE A+1 is greater than or equal to B
ENDIF

...is the same as: 

<QVAL <EVAL <LOCAL.A>+1> < <LOCAL.B> ? SYSMESSAGE A+1 is smaller than B:SYSMESSAGE A+1 is greater than or equal to B>

In the above statement, if we say that local.a=3 and local.b=5, then local.a+1=4

Since 4 is less that 5, the condition is true, and so the first output (before the : sign) in the true:false condition will be executed

If local.a=5 and local.b=5, then local.a+1=6

Since 6 is not less than 5, the condition will return as false and the second output (after the : sign) in the true:false result will be executed.

Your "if condition" is separated from the results by the ? character. The true and false results are separated by the : character (which is mandatory, even if you dont want anything to happen in one of the cases.)

Be careful if the true:false conditions also require you to use "greater than" It is easy to inadvertently close an argument too soon with a misplaced > after the ? or : in a QVAL argument. You should use always Less than ( < ) or Less or Equal ( <= )


The second QVAL Syntax

QVAL(VALUE1,VALUE2,LESSTHAN,EQUAL,GREATERTHAN)

This form of the QVAL statement is useful when comparing two values.

For example: 

<eval qval(<VAR.X>,<VAR.Y>,<VAR.ONE>,<VAR.TWO>,<VAR.THREE>)>

...will return <VAR.ONE> if X is less than Y, <VAR.TWO> if they are equal, and <VAR.THREE> if X greater than Y. If some of the arguments are omited like qval(1,2,,3) it will default to zero.

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