VBScript Reference Manual for InduSoft Web Studio

InduSoft Web Studio VBScript Reference Manual
Concatenation Operator (&)
Description Forces string concatenation of two expressions.
Usage result = expression1 & expression2
Arguments result
Any variable..
expression1
Any expression.
expression2
Any expression.
Return Result will be converted to a string subtype if it is not already
Remarks Whenever an expression is not a string, it is converted to a String subtype. If both
expressions are Null, result is also Null. However, if only one expression is Null, that
expression is treated as a zero-length string ("") when concatenated with the other
expression. Any expression that is Empty is also treated as a zero-length string.
Note: In addition to the & operator, you can also use the + operator for string
concatenation, although use of the & operator is the preferred method.
Example: Dim str1, str2, str3
str1 = “AB”
str2 = “CD”
str3 = str1 & str2 ‘ str3 equals “ABCD”
Concatenation Operator (+)
Description Concatenates two strings.
Usage result = expression1 + expression2
Arguments result
Any numeric or string variable.
expression1
Any valid numeric or string expression.
expression2
Any valid numeric or string expression.
Result Either numeric or string, depending on the arguments
Remarks Although you can also use the + operator to concatenate two character strings, you should use
the & operator for concatenation to eliminate ambiguity and provide self-documenting code.
When you use the + operator, you may not be able to determine whether addition or string
concatenation will occur.
The underlying subtype of the expressions determines the behavior of the + operator in the
following way:
If Then
Both expressions are numeric Add
Both expressions are strings Concatenate
One expression is numeric and the
other is a string Add
If one or both expressions are Null expressions, result is Null. If both expressions are Empty,
result is an Integer subtype. However, if only one expression is Empty, the other expression is
returned unchanged as result.
See also Addition Operator (+),Concatenation Operator (&), Subtraction Operator (-)
Example: a = “ABC” :
b = “DEF”
c = a + b ‘ Variable c is now “ABCDEF”
a = 1
b = “1”
c = a + b ‘ Variable c is now 2 (numeric value)
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