if-statement - IF语句-如何减少/简化源代码量

Question

我在尝试减少我的函数的这段代码时遇到麻烦：

checkData(day, month, year, area)
{
    if(area == "year" && year == this.year)
        return true;

    if(area == "month" && month == this.div && year == this.year)
        return true;

    if(area == "day" && day == this.day && month == this.div && year == this.year)
        return true;

    return false;
}

如何简化/减少这些IF子句的源代码量？

Answer 1

您的if子句可以重写为：

checkData(day, month, year, area)
{
    if(year == this.year) {
        if(area == "year") return true;
        if(month == this.div) {
            if(area == "month") return true;
            if(day == this.day) {
                if(area == "day") return true;
                return false;
            }
        }
    }
}

然后：

checkData(day, month, year, area)
{
    if(year != this.year) return false;
    if(area == "year") return true;
    if(month != this.div) return false;
    if(area == "month") return true;
    if(day != this.day) return false;
    return area == "day";
}

根据编程语言（例如C ++），另一种可能的语法：

checkData(day, month, year, area)
{
    return
        year != this.year ? false : 
        area == "year" ? true :
        month != this.div ? false :
        area == "month" ? true :
        day != this.day ? false :
        area == "day";
}

然后可以将其写成一行：

checkData(day, month, year, area)
{
    return year != this.year ? false : area == "year" ? true : month != this.div ? false : area == "month" ? true : day != this.day ? false : area == "day";
}

某些语言支持这种语法（例如C＃）：

checkData(day, month, year, area) => year != this.year ? false : area == "year" ? true : month != this.div ? false : area == "month" ? true : day != this.day ? false : area == "day";