How can I know the callback is invoked for the last time?

Question

According to String.prototype.replace() When I pass a function to String.replace(), the function will be invoked multiple times, if the regular expression is global.

How can I pass a callback to this callback to know when all invocations are done?

Answer 1

You do not need a callback. String.prototype.replace is a synchronous operation, therefore the code executes sequentially.

var s = 'test_test_test';

s = s.replace(/test/g, function () { return ''; });

console.log('replace done: ' + s);