The while condition extends the loop with a condition, as you will see in the following code snippet:

while (condition) 
{ 
    // do something 
} 

Let's take a look at the following example:

fn main() { 
    let mut done = 0u32; 
    while done != 32 
    { 
        println!("done = {}", done); 
        done += 1; 
    } 
} 

The preceding code will output done = 0 to done = 31. The loop terminates when done equals 32.