Javascript将变量值​​从一个函数传递到另一个函数

Question

每当我调用check_scroll() 函数时，我都需要将值 7 作为参数传递。

但是现在lastcount 的值不断增加，即使我调用了check_scroll() 函数。

请给我一些建议。

像我说的那样检查代码 sn-p，

首先单击first click me to initiate check_scroll function 按钮，然后在div 内滚动，您会收到一个值增加7 的警报。

然后单击按钮，然后再次滚动，但现在警报不会从 7 开始。

  $("#mybutton").click(function() {

    check_scroll(7);

  })

  function check_scroll(val) {

    var lastcount = val;
    $('#notification_ul').scroll(function() {
      if ($('#notification_ul').scrollTop() + $('#notification_ul').innerHeight() == $('#notification_ul')[0].scrollHeight) {

            $("#notification_ul").append("<br/> Some Text Append <br/>");
            alert(lastcount);

        lastcount = lastcount + 7;
      }

    })
  }

div {
  width: 200px;
  height: 200px;
  overflow: auto;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="notification_ul">
  Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has
  survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing
  software like Aldus PageMaker including versions of Lorem Ipsum.
</div>

<button id="mybutton">
  first click me to initiate check_scroll function
</button>

Answer 1

• 只定义一次scroll 事件
• 将lastcount移到外面
• 当按钮被点击时，重置lastcount

$(function(){
    var lastcount = 0;

    $("#mybutton").click(function() {
        check_scroll(7);
    });

    $('#notification_ul').scroll(function() {
        if (lastcount !== 0) {
            if ($('#notification_ul').scrollTop() + $('#notification_ul').innerHeight() == $('#notification_ul')[0].scrollHeight) {
                $("#notification_ul").append("<br/> Some Text Append <br/>");
                console.log(lastcount);
                lastcount = lastcount + 7;
            }
        }
    });
});

function check_scroll(val) {
    lastcount = val;
}

Answer 2

参考您的建议后的最终答案，感谢你们的快速解决方案和建议。竖起大拇指

var lastcount = 7;
$("#mybutton").click(function() {
	check_scroll(7);
})

$('#notification_ul').scroll(function() 
{
     if ($('#notification_ul').scrollTop() + $('#notification_ul').innerHeight() == $('#notification_ul')[0].scrollHeight) 
     {
		
    $("#notification_ul").append("<br/> Some Text Append <br/>");
    
    alert("last count after scroll " + lastcount);
		
    lastcount = lastcount + 7;
     }

})

function check_scroll(val) {
	lastcount = val;
	alert("Last count reseted to " + lastcount);
}

div {
  width: 200px;
  height: 200px;
  overflow: auto;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="notification_ul">
  Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has
  survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing
  software like Aldus PageMaker including versions of Lorem Ipsum.
</div>

<button id="mybutton">
  sometext
</button>