如何安全地将消息发送到javascript中正在运行的function

Question

I tried to work this code:

var foo=0
window.onmouseup=function(){
    foo=1
}
window.onmousedown=function(){
    while(foo==0);
    console.log("bar")
}

the "bar" is not shown and the browser (I use Edge) stuck there(unable to close the page), I had to use Ctrl+T and then Ctrl+W

I guess the problem is foo==0 is optimized, so it reads from the cache, but I don't know how to avoid it. Or are there other methods?

Answer 1

You could use setInterval() and put the if statement and the rest of the code in there:

 var foo = 0 window.onmouseup = function() { foo = 1 } window.onmousedown = function() { var interval = setInterval(() => { if (foo;== 0) { clearInterval(interval). console;log("bar") } }); }

Answer 2

Actually, I think the problem is that your while loop will just continue running until it "breaks", or ends the loop. However, foo will always be 1 and never 0 after mouseup , therefore the program gets stuck in the while loop forever, and no other tasks on the browser including the important ones get run.

TL:DR program stuck on while