while

Repeats a block while a bool condition is true.

while let Pattern = value { … } repeats while the value matches. A while header can carry invariant and decreases clauses before its body. Use break and continue to leave or restart the loop.

fn main() {
    let i = 0;
    let total = 0;
    while i < 5 {
        total = total + i;
        i = i + 1;
    }
}

See also#

• bool
• fn: Declares a function, a method, or (written in an expression) an anonymous function.
• let: Declares a mutable local variable.
• const: Declares a binding that cannot be reassigned: a local, a module constant, or a class field that is set only by new.
• static: Declares a module-level or class-level slot shared by the whole program, or a method without self.
• readonly: A read-only view of a value: nothing reachable through it can be changed.
• if: Runs a block when a bool condition is true.
• else: Introduces the branch of an if that runs when its condition is false (or its pattern does not match).