Switch 语句，它不适用于提示 [英] Switch Statement, it does not work with prompt

问题描述

我刚刚学习了 switch 语句.我通过建造一些东西来练习它.当我将变量的值设置为一个数字时，它可以工作，但是当我向用户询问一个数字时，它总是输出默认语句.

I just learned switch statements. I was practicing it by building something. When i set the value of variable to a number it works but when i asks the user for a number it always outputs the default statement.

它适用于以下代码:

confirm("You want to learn basic counting?");
var i = 0;
switch (i) {
    case 0:
        console.log(i);
        i++
    case 1:
        console.log(i);
        i++;
    case 2:
        console.log(i);
        i++;
    case 3:
        console.log(i);
        i++;
    case 4:
        console.log(i);
        i++;
    case 5:
        console.log(i);
        i++;
    case 6:
        console.log(i);
        i++;
    case 7:
        console.log(i);
        i++;
    case 8:
        console.log(i);
        i++;
    case 9:
        console.log(i);
        i++;
    case 10:
        console.log(i);
        console.log("Congratulations!");
        break;
    default:
        console.log("Buzz, wronghh");
        break;
}

但是当我向用户询问价值时，它不起作用.下面的代码不起作用:

But when i asks value from user, it dosen't work. Code below doesn't work:

confirm("You want to learn basic counting?");
var i = prompt("Type any number from where you want to start counting[Between 0 and 10]");
switch (i) {
    case 0:
        console.log(i);
        i++
    case 1:
        console.log(i);
        i++;
    case 2:
        console.log(i);
        i++;
    case 3:
        console.log(i);
        i++;
    case 4:
        console.log(i);
        i++;
    case 5:
        console.log(i);
        i++;
    case 6:
        console.log(i);
        i++;
    case 7:
        console.log(i);
        i++;
    case 8:
        console.log(i);
        i++;
    case 9:
        console.log(i);
        i++;
    case 10:
        console.log(i);
        console.log("Congratulations!");
        break;
    default:
        console.log("Buzz, wronghh");
        break;
}

推荐答案

您需要将用户输入从字符串转换为整数，就像这样

You need to convert the user input from a string to an integer, like so

confirm("You want to learn basic counting?");
var i = prompt("Type any number from where you want to start counting[Between 0 and 10]");
i = parseInt(i); // this makes it an integer
switch(i) {
//...

这篇关于Switch 语句，它不适用于提示的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！