JS face test--use for loop to print 1-10, each number appears at the interval of about 500MS

Again to brush face questions, haha.

Requirements: Use for loop to print 1-10, each number appears at an interval of about 500ms.

Analysis: Research points-closures, block-level scopes

Mode one, the use of closures + immediately execute the function, his thoughts at that time also think so, but the results do not reflect the interval 500ms

for (var i = 1; i <=; i++) {             setTimeout (function (i) {                 console.log (i);                 }) (i), (a);           }

After modification, the result satisfies the requirement: 1.setTimeout each time interval 500*i, guaranteed every 500ms output 2. Move immediate execution to the outer layer

/** * Using a For loop to print 1-10, each number appears at an interval of approximately 500ms * method one, using closures, note settimeout, every 500ms, so the interval between each pass is multiplied by I */for (var i=1;i<=10;i++) {    (function (i) {        setTimeout (function () {            console.log (i);        },500*i);    }) (i);}

Method two, using Let,let itself is a block-level scope

for (let i=1;i<=10;i++) {    setTimeout (function () {        console.log (i);    },500*i);}

　　

JS face test--use for loop to print 1-10, each number appears at the interval of about 500MS