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The value null is a special data type that indicates that a variable is empty, a condition that is different from being undefined. A null variable holds no value, though it might have previously. The null type is represented literally by the identifier, null. Since ScriptEase automatically converts data types, null is both useful and versatile. The code fragment above will work if undefined is changed to null, as shown in the following:


var test;

if (test == null)

   Screen.write("test is undefined")


Since null has a literal representation, assignments like the following are valid:


var test = null;


Any variable that has been assigned a value of null can be compared to the null literal.


The value null is an internal standard ECMAScript value. However, the value NULL is defined as 0 in seutil.jsh and is used in some scripts as it is found in C based documentation. Because of automatic conversion in JavaScript, the two values often operate alike, but not always. They are two separate values.