Question

Write the following compound statements as equivalent simple statements. a. \(\quad x+=5-z\) b. \(\quad y^{*}=2 * x+5-z\) c. \(\quad w+=2 * z+4\) d. \(x-z+y-t\) e. sum \(+=\) num

Short answer

a. \(x = x + (5-z)\), b. \(y = y * (2x + 5 - z)\), c. \(w = w + (2z + 4)\), d. \(x-z+y-t\), e. \(\text{sum} = \text{sum} + \text{num}\).

Step-by-step solution

Simplify Statement a

The compound statement given is \( x += 5 - z \). The operator += means 'add and assign'. Thus, you add \( 5 - z \) to \( x \). So, the simple statement would be: \( x = x + (5 - z) \).

Simplify Statement b

The compound statement is \( y^{*}= 2 * x + 5 - z \). The operator *= means 'multiply and assign'. Therefore, multiply \( y \) by the expression and assign it back to \( y \). The equivalent simple statement is: \( y = y * (2x + 5 - z) \).

Simplify Statement c

Given statement is \( w += 2 * z + 4 \). Again, += denotes 'add and assignment'. Thus \( 2 * z + 4 \) is added to \( w \). The equivalent simple statement is: \( w = w + (2z + 4) \).

Simplify Statement d

The statement \( x - z + y - t \) is already a simple arithmetic expression and does not require simplification with assignment operators. So, it remains: \( x - z + y - t \).

Simplify Statement e

The compound statement is \( \text{sum} += \text{num} \). Again, += means 'add and assign', so the statement is equivalent to:\( \text{sum} = \text{sum} + \text{num} \).

Key concepts

Compound Statements

In C++, a compound statement refers to a combination of operations that can be performed with a single line of code. Such statements often make use of compound assignment operators, like "+=", "-=", "*=", etc. These operators simultaneously perform a calculation and then assign the result back to the variable.

• The idea is to make the code more concise while preserving readability.
• For example, a statement like x += 5 - z is a compound statement that combines addition with an assignment.
• To break it down into a simpler form, you could rewrite this as x = x + (5 - z).

Such simplification helps in understanding and tracking changes that happen to variables throughout the code.

Simple Statements

Simple statements in C++ consist of basic operations that are broken down into the most fundamental sequence of instructions. Each statement accomplishes one primary task, such as initialization, arithmetic operation, or output.

• For a programmer, this means that each line, like x = x + 1, should ideally do one job at a step-by-step level.
• Simple statements are foundational and easy to read or debug because each represents a single straightforward computation.

This clarity is crucial in programming where every executed line should be easy to follow or modify at any time. So, transforming a compound expression into a series of simple statements can be useful for beginners or to troubleshoot complex algorithms.

Assignment Operators

Assignment operators in C++ are symbols used to accompany variable assignments in both simple and compound forms. While the regular "=" operator assigns right-hand values to the left-hand variable, compound assignment operators like "+=", "-=", "*=", and "/=" perform an additional computation too.

• For instance, with x += 3, the operation means "take the current value of x, add 3 to it, and then store the result back into x."
• This type of coding, while sometimes less verbose, maintains operations more succinctly, boosting readability when used correctly.

Knowing how and when to use assignment operators constructively can not only shorten your code but also enhance its efficiency.

Arithmetic Expressions

Arithmetic expressions are at the core of any program, performing a combination of basic operations like addition, subtraction, multiplication, and division. They can be as simple as a + b or extend to more complex formulas.

• These expressions often appear within conditionals, loops, and function calls.
• A strong grasp of how to construct arithmetic expressions correctly ensures that your logic remains flawless and conclusions drawn from calculations are accurate.

For developers, it's key to understand not just the calculations themselves but the order in which operations are executed (operator precedence), as well as the proper use of parentheses to alter that order for desired outcomes.