Rust tutorials for Python DEV: if statements

Beginner's Guide to Using if Statements in Rust

The if statement in Rust allows you to execute code conditionally, depending on whether an expression evaluates to true or false. This is similar to how if statements work in Python, but with some syntax differences.

Basic if Statement

In Python, you might write an if statement like this:

Python:

x = 5
if x > 3:
    print("x is greater than 3")

In Rust, the syntax is slightly different but serves the same purpose:

Rust:

fn main() {
    let x = 5;
    if x > 3 {
        println!("x is greater than 3");
    }
}

Breaking Down the Code

1. Define the Variable:

   let x = 5;

This creates a variable x with the value 5.

1. If Statement:

   if x > 3 {
       println!("x is greater than 3");
   }

This checks if x is greater than 3. If the condition is true, it executes the code inside the curly braces.

if-else Statement

You can add an else block to execute code when the condition is false.

Python:

x = 2
if x > 3:
    print("x is greater than 3")
else:
    print("x is not greater than 3")

Rust:

fn main() {
    let x = 2;
    if x > 3 {
        println!("x is greater than 3");
    } else {
        println!("x is not greater than 3");
    }
}

Breaking Down the Code

1. If-Else Statement:

   if x > 3 {
       println!("x is greater than 3");
   } else {
       println!("x is not greater than 3");
   }

If the condition x > 3 is true, it executes the first block. Otherwise, it executes the code in the else block.

else if Statement

For multiple conditions, you can use else if.

Python:

x = 5
if x > 10:
    print("x is greater than 10")
elif x > 5:
    print("x is greater than 5 but less than or equal to 10")
else:
    print("x is 5 or less")

Rust:

fn main() {
    let x = 5;
    if x > 10 {
        println!("x is greater than 10");
    } else if x > 5 {
        println!("x is greater than 5 but less than or equal to 10");
    } else {
        println!("x is 5 or less");
    }
}

Breaking Down the Code

1. Else If Statement:

   if x > 10 {
       println!("x is greater than 10");
   } else if x > 5 {
       println!("x is greater than 5 but less than or equal to 10");
   } else {
       println!("x is 5 or less");
   }

This checks multiple conditions in sequence. It executes the first block where the condition is true.

Using if in a let Statement

In Rust, you can use if expressions to assign values.

Python:

x = 10
y = "greater than 5" if x > 5 else "5 or less"

Rust:

fn main() {
    let x = 10;
    let y = if x > 5 {
        "greater than 5"
    } else {
        "5 or less"
    };
    println!("y is {}", y);
}

Breaking Down the Code

1. If Expression in Let Statement:

   let y = if x > 5 {
       "greater than 5"
   } else {
       "5 or less"
   };

This uses an if expression to assign a value to y based on the condition.

Conclusion

The if statement in Rust is a powerful tool for controlling the flow of your program based on conditions. It is similar to if statements in Python but with slight syntax differences. You can use if, else if, and else to handle multiple conditions and even use if expressions to assign values. Happy coding!

Python:

x = 2
if x > 3:
    print("x is greater than 3")
else:
    print("x is not greater than 3")

Rust:

fn main() {
    let x = 2;
    if x > 3 {
        println!("x is greater than 3");
    } else {
        println!("x is not greater than 3");
    }
}

Breaking Down the Code

1. If-Else Statement:

   if x > 3 {
       println!("x is greater than 3");
   } else {
       println!("x is not greater than 3");
   }

If the condition x > 3 is true, it executes the first block. Otherwise, it executes the code in the else block.

else if Statement

For multiple conditions, you can use else if.

Python:

x = 5
if x > 10:
    print("x is greater than 10")
elif x > 5:
    print("x is greater than 5 but less than or equal to 10")
else:
    print("x is 5 or less")

Rust:

fn main() {
    let x = 5;
    if x > 10 {
        println!("x is greater than 10");
    } else if x > 5 {
        println!("x is greater than 5 but less than or equal to 10");
    } else {
        println!("x is 5 or less");
    }
}

Breaking Down the Code

1. Else If Statement:

   if x > 10 {
       println!("x is greater than 10");
   } else if x > 5 {
       println!("x is greater than 5 but less than or equal to 10");
   } else {
       println!("x is 5 or less");
   }

This checks multiple conditions in sequence. It executes the first block where the condition is true.

Using if in a let Statement

In Rust, you can use if expressions to assign values.

Python:

x = 10
y = "greater than 5" if x > 5 else "5 or less"

Rust:

fn main() {
    let x = 10;
    let y = if x > 5 {
        "greater than 5"
    } else {
        "5 or less"
    };
    println!("y is {}", y);
}

Breaking Down the Code

1. If Expression in Let Statement:

   let y = if x > 5 {
       "greater than 5"
   } else {
       "5 or less"
   };

This uses an if expression to assign a value to y based on the condition.

Conclusion

The if statement in Rust is a powerful tool for controlling the flow of your program based on conditions. It is similar to if statements in Python but with slight syntax differences. You can use if, else if, and else to handle multiple conditions and even use if expressions to assign values. Happy coding!