Node.js: setTimeout の使い方

プログラム

timeout_test.js

#! /usr/local/bin/node
//	timeout_test.js
//
//						Feb/08/2023
//
// ---------------------------------------------------------------
'use strict'
// ---------------------------------------------------------------
function first_function(aa,bb)
{
	console.error("This is the first function")
	console.error("aa = " + aa)
	console.error("bb = " + bb)
	const sum = aa + bb
	console.error("first: sum = " + sum)
}

// ---------------------------------------------------------------
function second_function(aa,bb)
{
	console.error("This is the second function")
	console.error("aa = " + aa)
	console.error("bb = " + bb)
	const diff = aa + bb
	console.error("second: diff = " + diff)
}

// ---------------------------------------------------------------
function third_function(aa,bb)
{
	console.error("This is the third function")
	console.error("aa = " + aa)
	console.error("bb = " + bb)
	const sum = aa + bb
	console.error("third: sum = " + sum)
}

// ---------------------------------------------------------------
console.error ("*** 開始 ***")
setTimeout(() => first_function(12,34), 1000)
setTimeout(() => second_function(45,56), 2000)
setTimeout(() => third_function(71,82), 3000)
setTimeout(() => {console.error("*** 終了 ***")}, 4000)

console.error ("*** check bbb ***")

// ---------------------------------------------------------------

実行結果

$ ./timeout_test.js 
*** 開始 ***
*** check bbb ***
This is the first function
aa = 12
bb = 34
first: sum = 46
This is the second function
aa = 45
bb = 56
second: diff = 101
This is the third function
aa = 71
bb = 82
third: sum = 153
*** 終了 ***

確認したバージョン

$ node --version
v19.6.0