Today's exercise involves a series of experiments, each investigating a different aspect of a fundamental C++ concept: the expression. The term expression can be defined as follows:
An expression is a sequence of one or more operands, and zero or more operators, that when combined, produce a value.
To illustrate, the sequence
12fits the definition of an expression, since it consists of one operand (12) and zero operators that combine to produce a value (12). Perhaps more familiarly, the sequence
2 + 3fits the definition of an expression, since it consists of two operands (2 and 3) and one operator (+) that combine to produce a value (5). Operands need not be constants: the sequence
2.5 * x - 1.0fits the definition of an expression, since it consists of three operands (2.5, x and 1.0) and two operators (*, -) that combine to produce a value (1 less than the product of 2.5 and x).
These last two examples have been arithmetic expressions, that is, expressions whose operators are familiar arithmetic operators. As we shall see in today's exercise, C++ provides a rich set of arithmetic operators, as well as many non-arithmetic operators that allow C++ programmers to construct non-arithmetic expressions.
Using what you have learned about Windows-95 and Visual C++, begin by creating a Visual C++ project in your labs folder named express.
We will use the file express.cpp as a software laboratory for most of the experiments in this exercise. Click on the preceding link, and use your browser's
File -> Save Asmenu choice to save this file in your express subdirectory within your labs directory. Then in your Developers Studio window, choose Project -> Add file... to add express.cpp to your project. You can then open the file and take a moment to study its contents.
The form of the C++ iostream interactive output statement can be given as follows:
cout << Expression1 << Expression2 << ... << ExpressionN;When execution reaches such a statement, Expression1 is evaluated and displayed, after which Expression2 is evaluated and displayed, after which ..., after which ExpressionN is evaluated and displayed. An output statement thus provides a simple "laboratory" in which we can "experiment" with expressions by building them and viewing the values they produce.
Below is a list of the experiments available for this exercise.
Your instructor will tell you which ones you can omit, if any.
For each experiment that you are to perform,
click its link and print a hard copy of the resulting web page.
Then record your experimental results on that hard copy.
Experiment 1: Simple Expressions
Experiment 2: Characters and Character Strings
Experiment 3: Arithmetic Expressions
Experiment 4: Relational Expressions
Experiment 5: Logical Expressions
Experiment 6: Operator Precedence
Experiment 7: Operator Associativity
Experiment 8: Expressions Containing Functions
Experiment 10: Constant Declarations
Experiment 11: Assignment Statements
Experiment 12: Assignment Associativity
Experiment 13: Assignment Shortcuts
Experiment 14: Increment and Decrement Expressions
Experiment 15: Input and Output Expressions
Expression, Simple Expression, Operand, Operator,
Operator Precedence, Operator Associativity,
Integer Division, Logical Operator, Boolean Operator,
Library Function, Variable Declaration,
Constant Declaration, Operator Chaining, Increment Expression,
Decrement Expression, Output Operator, Input Operator.
Forward to the Homework Projects
Experiments
Phrases you should now understand:
Submit:
Turn in to your instructor
the hard copies showing the results of each of your experiments,
plus a hard copy of your final version of
express.cpp.
Copyright 1998 by
Joel C. Adams. All rights reserved.