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Comparison and Logic Operations
Part:
1
2
This chapter describes:
- Numeric Comparisons
- Logical Operations
Notes and samples in this chapter are based Visual Basic 6.0.
Numeric Comparisons
Numeric comparisons are operations that:
- Operates on two numeric operands.
- Produces a Boolean value by applying the comparison operation specified by the operator.
There are 6 numeric comparison operations supported in VB:
- Equal to (=): Resulting (True) if two operands are numerically equal.
- Not equal to (<>): Resulting (True) if two operands are numerically not equal.
- Greater than (>): Resulting (True) if the first operand is numerically greater than the second operand.
- Less than (<): Resulting (True) if the first operand is numerically less than the second operand.
- Greater than or equal to (>=): Resulting (True) if the first operand is numerically greater than or
equal to the second operand.
- Less than or equal to (<=): Resulting (True) if the first operand is numerically less than or
equal to the second operand.
To show you how numeric comparison operations work, I wrote the following script, comparison_operation.html:
<html>
<body>
<!-- comparison_operation.html
Copyright (c) 2006 by Dr. Herong Yang. http://www.herongyang.com/
-->
<pre>
<script language="vbscript">
document.writeln(1 = 1)
document.writeln(1 <> 1)
document.writeln(9.9999e-1 > 9.99999e-1)
document.writeln(9.9999e-1 < 1)
document.writeln(9.9999e-1 >= 0.99999)
document.writeln(1.00000001 <= 1)
</script>
</pre>
</body>
</html>
Here is the output:
True
False
False
True
True
False
No surprises in the output. But the equal to operator sign (=) is identical to the assignment operator.
We need to be careful.
(Continued on next part...)
Part:
1
2
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