js同步异步问题，怎么调用带callback函数的时候改成同步

Question

vardoExe=function(a,callback){setTimeout(function(){console.log(a)if(callback)callback},100*Math.random())}varaTest=function(num){for(vari=0;i

Answer 1

vardoExe=function(a,callback){
setTimeout(function(){
console.log(a)
if(callback)callback()
},100*Math.random())
}vari=0;varaTest=function(){
if(i<10){
doExe(i,aTest)
i++;
}
}aTest()