Transcript VBScript - Advanced QTP

VBScript
Session 3
Dani Vainstein
1
What We learn Last seasson?
How to declare arrays.
Working with one dimensional a multidimensional arrays.
Working with Dynamic arrays.
Arrays utilities (Array,UBound, LBound)
Dani Vainstein
2
Subjets for Session 3
Const Statement.
Operators.
Arithmetic.
Comparision.
Logical.
Dani Vainstein
3
Constants
Const Statement
[Public | Private] Const constname = expression
A constant is a meaningful name that takes the place of a
number or string and never changes.
VBScript defines a number of intrinsic constants.
You create user-defined constants in VBScript using the
Const statement.
Dani Vainstein
4
Constants
Const Statement
You may want to adopt a naming scheme to differentiate constants
from variables.
This will prevent you from trying to reassign constant values while
your script is running.
For example, you might want to use a "vb" or "con" prefix on your
constant names, or you might name your constants in all capital
letters:
conMaxValue, vbMyValue, MY_VALUE
Differentiating constants from variables eliminates confusion as
you develop more complex scripts.
Const MyString = "This is my string."
Const MyAge = 19
Const CutoffDate = #6-1-97#
Dani Vainstein
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VBScript Operators
VBScript has a full range of operators, including
arithmetic operators, comparison operators,
concatenation operators, and logical operators.
When several operations occur in an expression, each
part is evaluated and resolved in a predetermined order
called operator precedence.
You can use parentheses to override the order of
precedence and force some parts of an expression to be
evaluated before others.
Operations within parentheses are always
performed before those outside.
Dani Vainstein
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VBScript Operators
When expressions contain operators from more than
one category, arithmetic operators are evaluated first,
comparison operators are evaluated next, and logical
operators are evaluated last.
Comparison operators all have equal precedence; that
is, they are evaluated in the left-to-right order in
which they appear.
Arithmetic and logical operators are evaluated in the
following order of precedence.
Dani Vainstein
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VBScript Operators
Arithmetic Operators
Exponentation operator
Symbol : ^
Description: Raises a number to the power of an exponent.
Syntax: result = number^exponent
Note: If either number or exponent is a Null expression, result is also Null.
Substraction operator
Symbol : Description: Finds the difference between two numbers or indicates the
negative value of a numeric expression.
Syntax: result = number1-number2 : -number
Note: If one or both expressions are Null expressions, result is Null. If an
expression is Empty, it is treated as if it were 0.
Dani Vainstein
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VBScript Operators
Arithmetic Operators
Multiplication operator
Symbol : *
Description: Multiplies two numbers.
Syntax: result = number1*number2
If one or both expressions are Null expressions, result is Null. If an
expression is Empty, it is treated as if it were 0.
Division operator
Symbol : /
Description: Divides two numbers and returns a floating-point result.
Syntax: result = number1/number2
Note: If one or both expressions are Null expressions, result is Null. If
an expression is Empty, it is treated as if it were 0.
Dani Vainstein
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VBScript Operators
Arithmetic Operators
Integer Division operator
Symbol : \
Description: Divides two numbers and returns an integer result.
Syntax: result = number1\number2
Note: Before division is performed, numeric expressions are
rounded to Byte, Integer, or Long subtype expressions.
If any expression is Null, result is also Null. Any expression that is
Empty is treated as 0.
Dani Vainstein
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VBScript Operators
Arithmetic Operators
Modulus arithmetic operator
Symbol : Mod
Description: Divides two numbers and returns only the remainder.
Syntax: result = number1 Mod number2
Notes: The modulus, or remainder, operator divides number1 by
number2 (rounding floating-point numbers to integers) and returns
only the remainder as result.
If any expression is Null, result is also Null. Any expression that is
Empty is treated as 0.
Dani Vainstein
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VBScript Operators
Arithmetic Operators
Addition operator
Symbol : +
Description: Sums two numbers.
Syntax: result = number1+number2
Note: 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.
Dani Vainstein
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VBScript Operators
Arithmetic Operators
Concatenation operator
Symbol : &
Description: Forces string concatenation of two expressions.
Syntax: result = expression1 & expression2
Notes: 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 zerolength string ("") when concatenated with the other expression.
Any expression that is Empty is also treated as a zero-length string.
Dani Vainstein
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VBScript Operators
Comparision Operators
Equality and Inequality operators
Symbol : =, <, <=, >, >=, <>
Description: Used to compare expressions.
Syntax: result = expression1 comparisonoperator expression2
Note: When comparing two expressions, you may not be able to easily
determine whether the expressions are being compared as numbers or as
strings.
In operator
Symbol : In
Description: Compares two object reference variables.
Syntax: result = object1 Is object2
Note: If object1 and object2 both refer to the same object, result is True;
if they do not, result is False.
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VBScript Operators
Logical Operators
Logical Conjuction (And) operator
Symbol
: Not
Description:
Syntax:
Performs logical negation on an expression.
result = Not expression
If Expression is
Dani Vainstein
The result is
True
False
False
True
Null
Null
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VBScript Operators
Logical Operators
Logical Conjuction (And) operator
Symbol : And
Description:
Syntax:
Dani Vainstein
Performs a logical conjunction on two expressions.
result = expression1 And expression2
If expression1 is
And expression2 is
The result is
True
True
True
True
False
False
True
Null
Null
False
True
False
False
False
False
False
Null
False
Null
True
Null
Null
False
False
Null
Null
Null
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VBScript Operators
Logical Operators
Logical disjuction (Or) operator
Symbol : Or
Description: Performs a logical disjunction on two expressions.
Syntax: result = expression1 Or expression2
Dani Vainstein
If expression1 is
And expression2 is
The result is
True
True
True
True
False
True
True
Null
True
False
True
True
False
False
False
False
Null
Null
Null
True
True
Null
False
Null
Null
Null
Null
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VBScript Operators
Logical Operators
Logical Exclusion (Xor) operator
Symbol : Xor
Description: Performs a logical exclusion on two expressions.
Syntax: result = expression1 Xor expression2
Dani Vainstein
If expression1 is
And expression2 is
The result is
True
True
False
True
False
True
False
True
True
False
False
False
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