code demo by var,let,const feature use node.js !
console . log ( "(t23 code demo by var,let,const feature use node.js !) " ) var messages = [ "showout=>1" , "showout =>2" , "showout=>3" ]; const cnt = 10 ; for ( var i = 0 ; i < messages . length ; i ++) { setTimeout ( function () { console . log ( "[loop1]:" + messages [ i ]); console . log ( "[loop1]:" + "t=" , t , "j=" , j , "cnt=" , cnt ); }, i * 1500 ); } var j = 10 ; let t = 10 ; for ( let i = 0 ; i < messages . length ; i ++) { setTimeout ( function () { console . log ( "[loop2]:" + messages [ i ], i ); console . log ( "[loop2]:" + "t=" , t , "j=" , j , "cnt=" , cnt ); }, i * 1500 ); t += 1 ; j += 1 ; } { var jj = 10 ; let tt = 10 ;