Question

好的，所以我必须为这个班的最后一个项目设计一个货币转换器。到目前为止，我已经获得了用户转换货币的if语句的if语句。但是问题是，我不确定如何为用户转换的第二种货币创建if语句，而不必在第一个选项的每个if语句中粘贴大量混乱的代码。

我已经尝试了一些创建具有我需要的功能的函数，但是我不确定是否可以或如何在原始函数中调用它。

此外，我打算用货币代码来在其下创建while循环，因此它会询问用户，然后根据代码的多少进行转换。为不同的货币保留了不同的金额。

function CurrencyConverter(){
    var cad = "CAD";
    var usd = "USD";
    var gbp = "GBP";
    var euro = "EUR";
    var yen = "JPY";
    var CurrencyCode = 0;
    var inputted_currency = prompt("What currency is your amount in?");

    if(inputted_currency == cad || inputted_currency == "Canadian" || inputted_currency == "Canadian Dollars"){
        CurrencyCode + 1;
        document.getElementById("FromCurrency").innerHTML = "CAD";
        var twoC = call(SecondCurrency);
    } 

    else if(inputted_currency == usd || inputted_currency == "American" || inputted_currency == "American Dollars"){
        CurrencyCode + 2;
        document.getElementById("FromCurrency").innerHTML = "USD";
        var converted_currency = prompt("What currency would you like to convert to?");
    }

    else if(inputted_currency == gbp || inputted_currency == "British" || inputted_currency == "British Pounds" || inputted_currency == "Pounds"){
        CurrencyCode + 3;
        document.getElementById("FromCurrency").innerHTML = "GBP";
        var converted_currency = prompt("What currency would you like to convert to?");
    }

    else if(inputted_currency == euro || inputted_currency == "European" || inputted_currency == "European Euros" || inputted_currency == "Euros"){
        CurrencyCode + 4;
        document.getElementById("FromCurrency").innerHTML = "EUR";
        var converted_currency = prompt("What currency would you like to convert to?");
    }

    else if(inputted_currency == yen || inputted_currency == "Japanese" || inputted_currency == "Japanese Yen" || inputted_currency == "Yen"){
        CurrencyCode + 5;
        document.getElementById("FromCurrency").innerHTML = "JPY";
        var converted_currency = prompt("What currency would you like to convert to?");
    }

    else if(inputted_currency == "Dollars"){
        var dollar = prompt("Alright, Canadian or American?");

        if (dollar == "American"){
            CurrencyCode + 2;
            document.getElementById("FromCurrency").innerHTML = "USD";
            var converted_currency = prompt("What currency would you like to convert to?");
        }

        else if(dollar == "Canadian"){
            CurrencyCode + 1;
            document.getElementById("FromCurrency").innerHTML = "CAD";
            var converted_currency = prompt("What currency would you like to convert to?");
        }

        else{alert("Sorry, that's not a valid option. Please enter either American or Canadian exactly")
                }       
    }

    else{alert("Sorry, that's not one of the supported currencies")

 }

}

我希望的最终产品是，一旦用户单击一个按钮，他们就输入要转换的货币和该货币的金额。然后，转换器可以根据所投放的货币以及金额显示不同的金额。

如果我能从根本上简化代码，或者以某种方式将主代码链接到另一个代码块，我将不胜感激。谢谢您到目前为止所花的时间。

Answer 1

我认为将一些信息放入两个对象中会大大受益。一个用于存储用户选择（国家，金额和目标国家），另一个用于将用户输入映射到国家信息。

var userInput = {
    countryFrom: null,
    amount: null,
    countryTo: null
};
var countryMapping: {
    'Canadian':{
        CurrencyCode: 1,
        countryCode: 'CAD',
    },
    'Canadian Dollars':{
        CurrencyCode: 1,
        countryCode: 'CAD',
    },
    //...repeat for all mappings
};

function currencyConverter(){
       // first prompt
       var inputted_currency = prompt("What currency is your amount in?");
       if(countryMapping.hasOwnProperty(inputted_currency)){
           var result = countryMapping[inputted_currency];
           var countryCode = result.countryCode;
           document.getElementById("FromCurrency").innerHTML = countryCode;
           //var CurrencyCode = result.CurrencyCode;
           userInput.countryFrom = countryCode;

           // second prompt
           var converted_currency = prompt("What currency would you like to convert to?");
           if(countryMapping.hasOwnProperty(converted_currency)){
               var secondResult = countryMapping[converted_currency];
               var countryCode = secondResult.countryCode;
               //var CurrencyCode = secondResult.CurrencyCode;
               userInput.countryTo = secondResult.countryCode;
           } else {
               alert("Sorry, that's not one of the supported currencies")
           }
       } else {
           alert("Sorry, that's not one of the supported currencies")
       }
}

这不能处理从用户那里获取金额的问题。另外，我没有处理CountryCode，正如其他用户提到的那样，如果未将其分配给变量，则不会执行任何操作。

如何在Javascript函数中创建另一个代码块的快捷方式？

1 个答案: