javascript - 如何从外部 js 文件中的 JSON 数组获取变量？

Question

我有一个外部 JS 文件，其中包含 JSON 数组和函数，可帮助我选择一组随机变量。当我尝试在主 HTML 文件中生成结果时，p 标记中没有显示任何内容。我是否不匹配任何对象或变量？

正文部分 HTML 文件的简短示例

<p id="result"></p>
<script src="myJSfile.js" type="text/javascript">
<script language="javascript" type="text/javascript">
document.getElementById("result").innerHTML = lottery(selected.name + selected.age);
</script>

外部 JS 文件的简短示例

function lottery() {
var from, to, selected=new Array();
var person=
    [
     {"name":"Georgia","age":"45"},
     {"name":"John","age":"38"},
     {"name":"Michael","age":"29"},
    ];
    if (arguments[0] == "all") {
      from=0;
      to=person.length;
    }
    else {
      from=Math.floor(Math.random()*3);
      to=Math.floor(Math.random()*3+1);
    }
    for (i=0; i<to; i++) {
        selected[i]=person[from];
        from=(from+1)%3;
    }
    return selected;
   }

Answer 1

您的 from、to 和 selected 变量在函数外部不可见，只需将此行 var from, to, selected =new Array(); 脱离函数，它应该可以工作。

全部

var from, to, selected = new Array();
lottery('all');
for(var k = 0; k < selected.length; k++){
  document.getElementById("result").innerHTML += selected[k].name + " " + selected[k].age+'<br />';
}

function lottery() {
var person =
    [
     {"name":"Georgia","age":"45"},
     {"name":"John","age":"38"},
     {"name":"Michael","age":"29"},
    ];
    
    if (arguments[0] == "all") {
      from = 0;
      to = person.length;
    }
    else {
      from = Math.floor(Math.random()*3);
      to = Math.floor(Math.random()*3+1);
    }
    
    for (i = 0; i < to; i++) {
        selected[i] = person[from];
        from = (from+1)%3;
    }
    
    return selected;
    
   }

<p id="result"></p>

随机

var from, to, selected = new Array();
lottery('all');
for(var k = 0; k < selected.length; k++){
  document.getElementById("result").innerHTML += selected[k].name + " " + selected[k].age+'<br />';
}

function lottery() {
var person =
    [
     {"name":"Georgia","age":"45"},
     {"name":"John","age":"38"},
     {"name":"Michael","age":"29"},
    ];
    
    if (arguments[0] == "alla") {
      from = 0;
      to = person.length;
    }
    else {
      from = Math.floor(Math.random()*3);
      to = Math.floor(Math.random()*3+1);
    }
    
    for (i = 0; i < to; i++) {
        selected[i] = person[from];
        from = (from+1)%3;
    }
    
    return selected;
    
   }

<p id="result"></p>