Conteúdo do Curso
Introduction to JavaScript
Introduction to JavaScript
do while
Let's consider the do-while loop. This loop is similar to the while loop but has a key distinction.
while | do-while |
Executes code block after the condition check. | Executes code block before the condition check. |
Syntax
The do-while loop begins with the do
keyword, encloses the code block within curly braces {}
, and concludes with the while
keyword followed by the condition in parentheses ()
without the need for an additional code block:
Here's an example:
let a = 0; do { console.log(a); a++; } while (a <= 3 && a >= 1);
At the outset, the variable a
was initialized to 0
, and the condition a >= 1
was evaluated after the a++
operation.
The code block within the do
is guaranteed to be executed at least once:
// `while` loop while (false) { console.log("while"); // Not executed } // `do-while` loop do { console.log("do-while"); // Executed 1 time } while (false);
The do-while loop is particularly useful when you need to prompt the user for input at least once and continue until the user enters valid data or meets a specific condition.
Obrigado pelo seu feedback!