Null object: Difference between revisions
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=={{header|REXX}}== |
=={{header|REXX}}== |
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REXX can have variables with a null value. |
REXX can have variables with a null value. |
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<br>With the |
<br>With the '''symbol''' built-in function, it can be determined if a variable is defined (or not). |
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<br>The |
<br>The '''length''' built-in function can be used to see what the length of the value of a defined variable. |
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<br>A variable with a |
<br>A variable with a '''null''' value has a length of 0 (zero). |
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<br><br>The DROP statement can be used to "un-define" a REXX variable. |
<br><br>The '''DROP''' statement can be used to "un-define" a REXX variable. |
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<lang rexx>/*REXX program demonstrates null strings, and also undefined values. */ |
<lang rexx>/*REXX program demonstrates null strings, and also undefined values. */ |
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