Question

当我声明if语句以检查用户是否输入数字而不是直接字或字母时，它会说“不是有效输入，请输入您的回复作为数字。”但是，一旦你在警告框中单击“确定”，当它显示该消息时，您在提示中键入的消息是错误的或者数字仍然会被放入对象中。

如果你输入其他数字而不是数字，我怎么能这样做呢？它会继续说“不是有效的输入，请输入你的回复作为数字”，直到你输入数字？

var storeUsersInfo = [];
var amountOfUsers = prompt("How many users do you want?");
amountOfUsers = parseInt(amountOfUsers);
function returnUserInput() {
    var askFirstName = prompt("What is your first name?");
    var askLastName = prompt("What is your last name" + " " +     titleCase(askFirstName) + "?");
    var askAge = prompt("How old are you" + " " + titleCase(askFirstName) +  " " + titleCase(askLastName) + "?");

if(!Number.isInteger(Number.parseInt(askAge))) {
    alert("Not a valid input, please enter your response as a number.");
};

    return {
        firstName: titleCase(askFirstName),
        lastName: titleCase(askLastName),
        age: askAge
    };
};
function titleCase(string) {
    return string.charAt(0).toUpperCase() + string.slice(1); 
};

for(var i = 0; i < amountOfUsers; i++) {
    storeUsersInfo[i] = returnUserInput();
}
console.log(storeUsersInfo);

Answer 1

而是以递归方式再次向您的函数显示警报调用。

if(!Number.isInteger(Number.parseInt(askAge))) {
    returnUserInput()
};

它会一次又一次地提示，直到反应没问题。

Answer 2

将prompt，检查和alert置于循环中：

function returnUserInput() {
    var askFirstName = prompt("What is your first name?");
    var askLastName = prompt("What is your last name" + " " +     titleCase(askFirstName) + "?");
    while (true) {
        var askAge = prompt("How old are you" + " " + titleCase(askFirstName) 
                            +  " " + titleCase(askLastName) + "?");
        if(Number.isInteger(Number.parseInt(askAge))) break; // OK, exit loop
        alert("Not a valid input, please enter your response as a number.");
    };
    return {
        firstName: titleCase(askFirstName),
        lastName: titleCase(askLastName),
        age: askAge
    };
};

如何重复某段代码

2 个答案: