如何仅一次调用一个函数？

Question

This code keeps repeating, but i want it to happen twice, after the functions call and then after the set period of time using setTimeout .

function alertit() {
     alert('code');
     setTimeout(alertit, 200);
}

alertit();

Answer 1

function alertit(callAgain) {
     alert('code');
     if (callAgain) setTimeout("alertit(false)", 200);
}

alertit(true);

Answer 2

function alertit() {
     alert('code');
}

alertit();
setTimeout(alertit, 200);

for example.

Answer 3

Could you try this

function alertit(){

    // guard code
    if ( alertit.times == 2 ) return ; // for 4 times, alertit.times == 4  
    alertit.times = alertit.times ?  ++alertit.times: 1;

    // your function logic goes here ..   
    alert( 'here function called ' + alertit.times  );

    setTimeout( alertit , 1000 );
}

alertit();

Answer 4

You can apply condition logic over here.

    var callfunc = true;
    function alertit() {
         alert('code');
      if(callfunc == true)
         setTimeout(function(){ callfunc = false; alertit();}, 200);
    }

    alertit();

Answer 5

if the call to setTimeout has to be inside:

function alertit() {
  var f = function () {
    alert('code');
  }
  f();
  setTimeout(f, 200);
}

alertit();

Answer 6

You can use two flags to achieve. count will make sure your method runs for two times and the execute flag makes sure only first time the timeout is set.

var execute = true;
var count = 0;

function alertit() {
    if (count < 2) {
        alert('code');
        if (execute) {
            setTimeout(alertit, 200);
            execute = false;
        }
    }

}

alertit();

I see I have given a similar answer like tangelo which is doing the same in simple, easy steps.

Answer 7

If you are interested in a more general approach, you could set up something like this:

function callMultipleTimes(func, count, delay) {
    var key = setInterval(function(){
        if (--count <= 0) {
            clearInterval(key);
        }
        func();
    }, delay);
}

function alertit() {
     alert('code');
}

callMultipleTimes(alertit, 2, 200);

FIDDLE

Answer 8

创建一个全局变量调用_Count = 0，并在函数alertit（）中执行if条件，如果（_Count <> 1）调用该函数，然后如果此条件为true，则递增变量并调用该函数...