Flow Control in Rust

Flow control in Rust refers to the mechanisms that determine the order in which code is executed. Understanding flow control is essential for writing effective programs. The main constructs for flow control in Rust include conditional statements, loops, and pattern matching.

Key Concepts

1. Conditional Statements

Conditional statements allow the execution of certain code blocks based on conditions.

else if Statement: Allows checking multiple conditions.

if number < 10 {
    println!("The number is less than 10");
} else if number == 10 {
    println!("The number is exactly 10");
} else {
    println!("The number is greater than 10");
}

else Statement: Provides an alternative code block if the if condition is false.

if number < 10 {
    println!("The number is less than 10");
} else {
    println!("The number is 10 or more");
}

if Statement: Executes code if a condition is true.

let number = 5;
if number < 10 {
    println!("The number is less than 10");
}

2. Loops

Loops enable repeated execution of code until a certain condition is met.

for Loop: Iterates over a range or collection.

for number in 1..6 {
    println!("{}", number); // Prints numbers from 1 to 5
}

while Loop: Continues executing as long as the condition is true.

let mut count = 0;
while count < 5 {
    println!("{}", count);
    count += 1;
}

loop Statement: An infinite loop that continues until explicitly broken.

let mut count = 0;
loop {
    count += 1;
    if count >= 5 {
        break;
    }
}

3. Pattern Matching

Pattern matching is a powerful control flow operator in Rust, often used with match statements.

match Statement: Compares a value against a series of patterns.

let number = 1;
match number {
    1 => println!("One"),
    2 => println!("Two"),
    _ => println!("Something else"), // Wildcard pattern
}

Conclusion

Flow control is fundamental to programming in Rust. By mastering conditional statements, loops, and pattern matching, beginners can create more complex and efficient programs. Each of these constructs serves a specific purpose and can be combined to handle various programming scenarios effectively.