Rust: What is the difference between match and if let?

match — exhaustive pattern matching (all cases). if let — single pattern match.

match:

• Exhaustive — compiler checks that every variant is handled.
• Supports guards, multiple patterns, and nested destructuring.
• Returns a value (expression).
• More verbose but more powerful.

1let value = Some(42);
2match value {
3    Some(x) if x > 100 => println!("Huge: {}", x),
4    Some(x) if x > 10 => println!("Big: {}", x),
5    Some(x) => println!("Small: {}", x),
6    None => println!("Nothing"),
7}
8
9// Returning a value
10let label = match value {
11    Some(n) => format!("Value: {}", n),
12    None => "Empty".into(),
13};

if let:

• Matches only one specific pattern.
• Simpler syntax for single-case checks.
• Can combine with else or else if let.
• Reduces boilerplate when you only care about one case.

1if let Some(value) = value {
2    println!("Got: {}", value);
3}
4
5// Chaining
6if let Some(x) = value {
7    println!("Got: {}", x);
8} else {
9    println!("Nothing");
10}

When to use:

• Use match for complex multi-case pattern matching.
• Use if let when you only care about one pattern.
• Use if let for cleaner code with simple fallbacks.

Common mistakes:

• Missing a variant in match — compiler error.
• Using if let when multiple cases need handling — use match.
• Not handling the "else" case when it matters.