Javascript 这孩子不工作
我正在研究嵌套数组。当我试图使用Javascript 这孩子不工作,javascript,arrays,Javascript,Arrays,我正在研究嵌套数组。当我试图使用appendChild向div插入数据时,它抛出了一个错误,表示无法读取null的属性“appendChild” 我的密码是听到的 <script> var emp1 = []; emp1["Emsno"] = 10001; emp1["name"] = "jack"; emp1 ["sall"] = 5000; var emp2 = []; emp2["Emsno"] = 10002; emp
appendChild
向div插入数据时,它抛出了一个错误,表示无法读取null的属性“appendChild”
我的密码是听到的
<script>
var emp1 = [];
emp1["Emsno"] = 10001;
emp1["name"] = "jack";
emp1 ["sall"] = 5000;
var emp2 = [];
emp2["Emsno"] = 10002;
emp2["name"] = "Reck";
emp2 ["sall"] = 5500;
var emp3 = [];
emp3["Emsno"] = 10003;
emp3["name"] = "lama";
emp3 ["sall"] = 5300;
var emp4 = [];
emp4["Emsno"] = 10004;
emp4["name"] = "sam";
emp4 ["sall"] = 6000;
var emps = [emp1, emp2, emp3, emp4];
var Employedisplay = document.getElementById("Employedisplay");
function showEmployes(){
var n = emps.length;
for (i = 0; i < n ; i++){
var emp = emps[i];
for(var key in emp){
var NewDiv = document.createElement("div");
NewDiv.innerHTML = key + ": " + emp[key];
Employedisplay.appendChild(NewDiv);
}
var NewBrk = document.createElement("br")
Employedisplay.appendChild(NewBrk);
}
}
</script>
</head>
<body>
<input type = "button" id = "MyArray" value ="Show Emps" onclick="showEmployes()"/>
<hr>
<div id="Employedisplay"></div>
</body>
var-emp1=[];
emp1[“Emsno”]=10001;
emp1[“名称”]=“杰克”;
emp1[“sall”]=5000;
var-emp2=[];
emp2[“Emsno”]=10002;
emp2[“名称”]=“Reck”;
emp2[“sall”]=5500;
var emp3=[];
emp3[“Emsno”]=10003;
emp3[“姓名”]=“喇嘛”;
emp3[“sall”]=5300;
var emp4=[];
emp4[“Emsno”]=10004;
emp4[“名称”]=“sam”;
emp4[“sall”]=6000;
var emps=[emp1,emp2,emp3,emp4];
var Employedisplay=document.getElementById(“Employedisplay”);
函数showEmployes(){
var n=电磁脉冲长度;
对于(i=0;i
它是这样工作的
function showEmployes(){
var n = emps.length;
for (i = 0; i < n ; i++){
var emp = emps[i];
for(var key in emp){
var NewDiv = document.createElement("div");
NewDiv.innerHTML = key + ": " + emp[key];
document.getElementById("Employedisplay").appendChild(NewDiv);
}
var NewBrk = document.createElement("br")
Employedisplay.appendChild(NewBrk);
}
}
函数showEmployes(){
var n=电磁脉冲长度;
对于(i=0;i
我不明白我的第一种方法哪里出错了?甚至在浏览器在DOM中添加
#employeedisplay
元素之前,下面的代码行也会执行
var Employedisplay = document.getElementById("Employedisplay");
因此,当您单击按钮时,employeedisplay
变量为null
最好在页面加载时引导代码,或者可以在showEmployee
方法的开头获取#employeedisplay元素
<script>
var emp1 = [];
emp1["Emsno"] = 10001;
emp1["name"] = "jack";
emp1["sall"] = 5000;
var emp2 = [];
emp2["Emsno"] = 10002;
emp2["name"] = "Reck";
emp2["sall"] = 5500;
var emp3 = [];
emp3["Emsno"] = 10003;
emp3["name"] = "lama";
emp3["sall"] = 5300;
var emp4 = [];
emp4["Emsno"] = 10004;
emp4["name"] = "sam";
emp4["sall"] = 6000;
var emps = [emp1, emp2, emp3, emp4];
function bootstrap() {
var Employedisplay = document.getElementById("Employedisplay");
}
function showEmployes() {
var n = emps.length;
for (i = 0; i < n; i++) {
var emp = emps[i];
for (var key in emp) {
var NewDiv = document.createElement("div");
NewDiv.innerHTML = key + ": " + emp[key];
Employedisplay.appendChild(NewDiv);
}
var NewBrk = document.createElement("br")
Employedisplay.appendChild(NewBrk);
}
}
</script>
</head>
<body onload="bootstrap();">
<input type="button" id="MyArray" value="Show Emps" onclick="showEmployes()" />
<hr>
<div id="Employedisplay"></div>
</body>
var-emp1=[];
emp1[“Emsno”]=10001;
emp1[“名称”]=“杰克”;
emp1[“sall”]=5000;
var-emp2=[];
emp2[“Emsno”]=10002;
emp2[“名称”]=“Reck”;
emp2[“sall”]=5500;
var emp3=[];
emp3[“Emsno”]=10003;
emp3[“姓名”]=“喇嘛”;
emp3[“sall”]=5300;
var emp4=[];
emp4[“Emsno”]=10004;
emp4[“名称”]=“sam”;
emp4[“sall”]=6000;
var emps=[emp1,emp2,emp3,emp4];
函数bootstrap(){
var Employedisplay=document.getElementById(“Employedisplay”);
}
函数showEmployes(){
var n=电磁脉冲长度;
对于(i=0;i
var-emp1=[];
emp1[“Emsno”]=10001;
emp1[“名称”]=“杰克”;
emp1[“sall”]=5000;
var-emp2=[];
emp2[“Emsno”]=10002;
emp2[“名称”]=“Reck”;
emp2[“sall”]=5500;
var emp3=[];
emp3[“Emsno”]=10003;
emp3[“姓名”]=“喇嘛”;
emp3[“sall”]=5300;
var emp4=[];
emp4[“Emsno”]=10004;
emp4[“名称”]=“sam”;
emp4[“sall”]=6000;
var emps=[emp1,emp2,emp3,emp4];
函数showEmployes(){
var Employedisplay=document.getElementById(“Employedisplay”);
var n=电磁脉冲长度;
对于(i=0;i
var Employedisplay=document.getElementById(“Employedisplay”)代码>在id为EmployeeDisplay
的元素存在之前执行。将文档末尾的
块移动到关闭
<script>
var emp1 = [];
emp1["Emsno"] = 10001;
emp1["name"] = "jack";
emp1 ["sall"] = 5000;
var emp2 = [];
emp2["Emsno"] = 10002;
emp2["name"] = "Reck";
emp2 ["sall"] = 5500;
var emp3 = [];
emp3["Emsno"] = 10003;
emp3["name"] = "lama";
emp3 ["sall"] = 5300;
var emp4 = [];
emp4["Emsno"] = 10004;
emp4["name"] = "sam";
emp4 ["sall"] = 6000;
var emps = [emp1, emp2, emp3, emp4];
function showEmployes(){
var Employedisplay = document.getElementById("Employedisplay");
var n = emps.length;
for (i = 0; i < n ; i++){
var emp = emps[i];
for(var key in emp){
var NewDiv = document.createElement("div");
NewDiv.innerHTML = key + ": " + emp[key];
Employedisplay.appendChild(NewDiv);
}
var NewBrk = document.createElement("br")
Employedisplay.appendChild(NewBrk);
}
}
</script>
</head>
<body>
<input type = "button" id = "MyArray" value ="Show Emps" onclick="showEmployes()"/>
<hr>
<div id="Employedisplay"></div>
</body>