免责声明:我是个白痴。
这非常简单。我一定是做了一些非常基本的错误,但我花了很多时间试图弄清楚,但我被难住了。
作为引用,整个代码:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Not comparing correctly</title>
</head>
<script>
//This is the main function. It creates a new game and plays it.
function playTheGame() {
"use strict";
//create the game object
var currentGame = new game();
//play the game
currentGame.play(document.getElementById("eCurrentStake").value, document.getElementById("eGoalAmount").value);
}
// This is the game object.
function game(){
//properties
this.goalAmount = 0;
this.currentStake = 0;
//Play method Plays the game and stores the results in properties
this.play=play;
function play(currentStake,goalAmount){
//set the relevant properties to values passed to the object
this.goalAmount = goalAmount;
this.currentStake = currentStake;
alert(this.currentStake+" < "+this.goalAmount+" :"+(this.currentStake < this.goalAmount));
};
}
</script>
<body>
Enter Current Stake: <input type="text" id="eCurrentStake"></input><br>
Enter Goal Amount: <input type="text" id="eGoalAmount"></input><br>
<button type="button" onclick="playTheGame()">Let's Play!</button>
</body>
</html>
给我带来麻烦的代码部分:
alert(this.currentStake+" < "+this.goalAmount+" :"+(this.currentStake < this.goalAmount));
当我将 9 和 10 输入到输入文本字段中时,我得到“false”输出。 但 10 和 50 确实返回 true。简而言之:结果是不可预测的。我认为它可能会作为字符串进行评估,但是当我研究它时,我所能发现的是 Javascript 具有动态数据类型,并且如果变量是数字,则会将变量作为数字进行比较。即:
http://www.w3schools.com/js/js_datatypes.asp
那么,我哪里出错了?
最佳答案
可能需要使用parseInt
将参数转换为数字:
this.goalAmount = parseInt(goalAmount);
this.currentStake = parseInt(currentStake);
关于javascript比较运算符无法正确评估用户输入,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18857240/