需要帮助将字符串转换为整数并添加用户输入

Question

我是编程课的入门课程，其中的作业采用视觉逻辑。 本周的课程是收集食物摄入量，卡路里摄入量和我能够在逻辑上做到的if陈述的作业。 下一类是网页设计，所以我想为什么不尝试在javascript中做同样的事情并获得一些javascript经验，但是我遇到了问题。 用户输入的卡路里未转换为整数，无法将这些值相加。 请帮助，我已经阅读，研究并尝试了多种方法。 代码如下

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Calorie Burner Program</title>
<script type="text/javascript">

</script>

</head>
<body>
<script type="text/javascript">
//I named my variables here
    var TotalCal, Food1, Cal1, Food2, Cal2, Food3, Cal3, Food4, Cal4, Food5, Cal5, Food6, Cal6, Food7, Cal7, Food8, Cal8, Food9, Cal9, Food10, Cal10, Food11, Cal11,    Food12, Cal12, Food13, Cal13, Food14, Cal14, Food15, Cal15, Food16, Cal16, Food17, Cal17, Food18, Cal18, Food19, Cal19, Food20, Cal20
    //i'm prompting for the food
    Food1 = window.prompt("What did you eat today?");
    //Here i'm prompting for calories and I would like to reference the input above.  as you can see from the code i've tried multiple suggestions
    Cal1 = parseInt(prompt("How many calories was " + Food1, "0"), 10);
    Food2 = window.prompt("What did you eat today?");
    Cal2 = parseInt(prompt("How many calories was " + Food2, "0"), 10);
    Food3 = window.prompt("What did you eat today?");
    Cal3 = window.prompt("How many calories was" + " " + Food3);
        ....
    Food20 = window.prompt("What did you eat today?");
    Cal120 = window.prompt("How many calories was" + " " + Food20)
    //you can see below that i've tried multiple methods and i get 5 everytime because my calories is 5 on every item i enter for testing
    TotalCal = Cal1, + Cal2, + +Cal3, + +Cal4, + +Cal5, + +Cal6, + +Cal7, + +Cal8, + +Cal9, + +Cal10,+ +Cal11, + +Cal12, + +Cal13, + +Cal14, + +Cal15, + +Cal16, +  +Cal17, + +Cal18, + +Cal19
    alert("The number of calories you consumed today was " + TotalCal);


    </script>
</body>
</html>

Answer 1

您正在寻找parseInt()函数。

var numStringOne = "1";
var numStringTwo = "2";

var numOne = parseInt(numStringOne);
var numTwo = parseInt(numStringTwo);

var sum = numOne + numTwo; 

> sum == 3 == true

Answer 2

使用加号将其转换为数字。

var numStringOne = "1";
var numStringTwo = "2";

var numOne = +numStringOne;
var numTwo = +numStringTwo;
var sum = numOne + numTwo;
if (sum === 3) {
    console.log("Hooray!");
}

这是一些有关此的阅读：

并建议另一个人建议使用parseInt() ：

http://speakingjs.com/es5/ch11.html#parseInt

需要帮助将字符串转换为整数并添加用户输入

问题描述

2 个解决方案

解决方案1
1 2015-03-02 03:19:57

解决方案2
0 已采纳 2015-03-02 03:31:01

需要帮助将字符串转换为整数并添加用户输入

问题描述

2 个解决方案

解决方案1 1 2015-03-02 03:19:57

解决方案2 0 已采纳 2015-03-02 03:31:01

解决方案1
1 2015-03-02 03:19:57

解决方案2
0 已采纳 2015-03-02 03:31:01