rustlings/exercises/error_handling/errors3.rs

32 lines
811 B
Rust
Raw Normal View History

2018-02-22 09:09:53 +03:00
// errors3.rs
2016-06-21 17:40:32 +03:00
// This is a program that is trying to use a completed version of the
2019-11-11 15:37:43 +03:00
// `total_cost` function from the previous exercise. It's not working though!
// Why not? What should we do to fix it?
// Execute `rustlings hint errors3` for hints!
2016-06-21 17:40:32 +03:00
// I AM NOT DONE
2016-06-21 17:40:32 +03:00
use std::num::ParseIntError;
fn main() {
let mut tokens = 100;
let pretend_user_input = "8";
2018-11-09 22:31:14 +03:00
let cost = total_cost(pretend_user_input)?;
2016-06-21 17:40:32 +03:00
if cost > tokens {
println!("You can't afford that many!");
} else {
tokens -= cost;
println!("You now have {} tokens.", tokens);
}
}
pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
let processing_fee = 1;
let cost_per_item = 5;
2018-11-09 22:31:14 +03:00
let qty = item_quantity.parse::<i32>()?;
2016-06-21 17:40:32 +03:00
Ok(qty * cost_per_item + processing_fee)
}