JS: do while | JavaScript
JavaScript do while
do while loop defines block of statements to iterate until the condition given in while at the end of the loop.
var i = 0;
do{
console.log(i++);
}
while(i < 10);
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do-while made first iteration with checking the condition. Checked the condition 9 times. 9th time, the loop exited (broken) because the condition i < 10 became false.
do-while executes at least once
do
console.log('do-while iterates at leasts once!');
while(false);
do-while iterates at leasts once!
Even the condition is false but the the console.log statement will be executed because the statement is checked later by while. The above code will always running if the condition was true instead of false.
Comparing while and do-while loops difference
whileloop checks the condition first and executes the statement(s) in the block until the condition remainstrue.dowhileexecutes the statement(s) in the block at least once.- The do-while loop keeps iterating (repeating) the the block of statements until the condition in
whileremainstrue. dowhileexited (broken) if the condition inwhilebecomesfalse.
Summary
dowhileexecutes statement(s) at least once in any case.whileis required at the end ofdo-whileloop.