我检查了一些类似问题的问题但无法应对我的文件.js:
'use strict'
function singlyLinkedList() {
if (this ) {
this.head = null
}
}
singlyLinkedList.prototype.append = function(value) {
let node = {
data: value,
next: null
}
if( !this.head ) {
this.head = node
} else {
let pointer = this.head
while( pointer ) {
pointer = pointer.next
}
pointer.next = node
}
}
我从index.html调用的:
<!DOCTYPE html>
<html>
<head>
<title> Test </title>
<meta charset="UTF-8">
<script src="file.js"></script>
</head>
<body>
<script>
let linkedList = singlyLinkedList()
let integersArray = [1, 22, 333, 4444]
integersArray.forEach(element => linkedList.append(element))
</script>
</body>
</html>
使用Chrome浏览器浏览此HTML文件并检查控制台,会显示以下错误消息:
未捕获的TypeError:无法读取undefined的属性'append'
如何解决这个问题?
更新:
我对此的第二个问题(也许是一个单独的问题?)是如果我写的:
function singlyLinkedList() {
this.head = null
}
我收到此错误消息:
未捕获的TypeError:无法设置未定义的属性'head'
你需要照顾的一些事情,
new
关键字创建'singlyLinkedList'的实例while
循环终止条件不正确。它应该是while( pointer.next )
检查以下版本,
//create a `file.js` file and put this code inside that. running this code snippet on stackoverflow util wont work as you need a separate `file.js`
'use strict';
function singlyLinkedList() {
this.head = null;
}
singlyLinkedList.prototype.append = function(value) {
let node = {
data: value,
next: null
};
if( !this.head ) {
this.head = node
} else {
let pointer = this.head;
while( pointer.next ) { //check this
pointer = pointer.next
}
pointer.next = node
}
};
<!DOCTYPE html>
<html>
<head>
<title> Test </title>
<meta charset="UTF-8">
<script src="file.js"></script>
</head>
<body>
<script>
let linkedList = new singlyLinkedList(); // check this
let integersArray = [1, 22, 333, 4444];
integersArray.forEach(element => linkedList.append(element));
console.log('linkedList: ', linkedList);
</script>
</body>
</html>
它会记录像,
而且我坚信你需要使用new
关键字来创建singlyLinkedList
函数的实例,因为你想要使用prototype
概念的好处