Hey,

I'm new in Rust and I have a question: Can't I create a vector with the length of a variable or constant?

```
const n: u128 = 1000;
let memo: vec![0; n];
```

This causes an error I don't understand.

Thank you.

Hey,

I'm new in Rust and I have a question: Can't I create a vector with the length of a variable or constant?

```
const n: u128 = 1000;
let memo: vec![0; n];
```

This causes an error I don't understand.

Thank you.

It’s just a syntax error

```
const n: u128 = 1000;
- let memo: vec![0; n];
+ let memo = vec![0; n];
```

well, and a type error, too, as the length of a vector needs to be a `usize`

:

```
- const n: u128 = 1000;
+ const n: usize = 1000;
let memo = vec![0; n];
```

or

```
const n: u128 = 1000;
- let memo = vec![0; n];
+ let memo = vec![0; n as usize]; // this wraps/overflows if n is too big
```

Variables are fully supported, too

```
let n = 1000;
let memo = vec![0; n];
```

1 Like

Thank you so much.

It worked

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