Example 2-10. Passing values in a sequence of steps

Promise.resolve('ta-da!').then(
	function step2(result) {
		console.log('Step 2 received ' + result);
		return 'Greetings from step 2'; // Explicit return value
	}
).then(
	function step3(result) {
		console.log('Step 3 received ' + result); // No explicit return value
	}
).then(
	function step4(result) {
		console.log('Step 4 received ' + result);
		return Promise.resolve('fulfilled value'); // Return a promise
	}
).then(
	function step5(result) {
		console.log('Step 5 received ' + result);
	}
);

// Console output:
// Step 2 received ta-da!
// Step 3 received Greetings from step 2
// Step 4 received undefined
// Step 5 received fulfilled value