When an Ajax loop is called, only the last value is returned, and the last data is executed in the background

1.

Code:
var i;
for (i=0;i<10;i++) {
Ajaxservise (i);
}

Calling the Ajax method in the for loop complements the data on the page, which is wrong, and does not execute the Ajax method every time the for loop is executed, but instead executes the Ajax method at the end of the For loop, which results in Ajax being executed only once . However when modified as follows:

for (i=0;i<10;i++) {
Alert ("AA");
Ajaxservise (i);
}
Unlike the above, a form alert pops up each time it is called ("content is free") so that the content is displayed correctly on the page instead of a single piece of content

Cause: The For loop is single-threaded in JS, he will execute the next step after the for loop, and alert closes the loop, letting the program respond once, and calling the Ajax method again, but we can't let the alert method appear in the program.

(This method is displayed correctly in the foreground, but is still the last value when the background data is called)
Workaround:
var i=0;
var sum=10;
var time;
Ajaxservise (i) {
if (i==sum) {
Cleartimeout (time);
}
i=i+1;
Time = SetTimeout (Ajaxservise (), 10);
........................
..................
............
......
}

This is called with the settimeout (Ajax ()) method, settimeout the method executes and then executes the Ajax () method again, with settimeout and cleartimeout to solve the problem perfectly.

Ps:settimeout is pseudo-multithreading.

2, whether to fill in the synchronization of the field.

When an Ajax loop is called, only the last value is returned, and the last data is executed in the background