CODEWITHSUNDEEP
rust
109149
109149

Reputation: 1552

How to write multiple condition in if let statement?

How to modify if let statement so it also handles another condition like Some(7) == b?

let a = Some(6);
let b = Some(7);
if let Some(6) = a /* && Some(7) = b */{
    // do something
}

Upvotes: 52

Views: 31105

Answers (3)

İsmail Furkan GÖKHASAN
İsmail Furkan GÖKHASAN

Reputation: 43

You can use zip function over Option type.

let a = Some(10);
let b = Some(5);

if let Some((x @ 10, y @ 5)) = a.zip(b) {
    // a and b is Some and has specified values.
} else {
    // a or b or both is none, or one of the values is not matched
}

Docs: https://doc.rust-lang.org/std/option/enum.Option.html#method.zip

Upvotes: 1

E_net4
E_net4

Reputation: 29972

The if let expression only admits one match arm pattern against one expression. However, they can be merged together into a single equivalent pattern match condition. In this case, the two Option values can be combined into a pair and matched accordingly.

if let (Some(6), Some(7)) = (a, b) {
    // do something
}

Playground

See also:

Upvotes: 23

Marco Bonelli
Marco Bonelli

Reputation: 69276

You can use a simple tuple:

if let (Some(6), Some(7)) = (a, b) {
    // do something
}

Upvotes: 91

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