Statements and Control Structures

Statements and Control Structures

This topic covers statements and control structures in C++. These are essential for controlling the flow of execution in your programs. Understanding how to use these structures allows you to create more complex and functional applications.

Types of Statements

In C++, statements are instructions that the compiler executes. They can be categorized into several types:

1. Expression Statements

An expression statement consists of an expression followed by a semicolon. For example:

int x = 5;

This statement declares a variable x and initializes it with the value 5.

2. Compound Statements

A compound statement groups multiple statements into a single block, enclosed in curly braces:

if (x > 0) {
    cout << "Positive";
}

3. Control Flow Statements

Control flow statements change the execution order of statements. These include:

• Conditional statements (if, else)
• Looping statements (for, while)
• Jump statements (break, continue)

Control Structures

Control structures allow you to control the flow of your program based on conditions.

1. Conditional Statements

Conditional statements execute different code blocks based on a condition. The most common are if and else.

if (x > 10) {
    cout << "x is greater than 10";
} else {
    cout << "x is 10 or less";
}

2. Loops

Loops allow you to execute a block of code multiple times. Common loop types are:

a. For Loop

for (int i = 0; i < 5; i++) {
    cout << i;
}

This loop will print the numbers 0 to 4.

b. While Loop

int j = 0;
while (j < 5) {
    cout << j;
    j++;
}

This loop will also print the numbers 0 to 4.

Type Casting

C++ allows type casting to convert one data type to another. You can use static_cast and const_cast for this purpose.

Example of Type Casting

double m2k = 1.609;
int miles = 23;
double kilometers = miles * m2k;
cout << static_cast(kilometers); // Outputs 37

In this example, static_cast converts kilometers from double to int.

Summary

• Statements are instructions executed by the compiler.
• Control structures manage the flow of execution.
• Conditional statements allow branching based on conditions.
• Loops enable repeated execution of code blocks.
• Type casting is used to convert data types.

Check your understanding

1. What is the difference between a statement and a control structure?
2. Write an example of a for loop that counts from 1 to 10.
3. Explain the purpose of static_cast in C++.
4. What could happen if you attempt to modify a const object using const_cast?