Java闰年逻辑错误
提问于 2015-10-26 03:57:45
下面是我的代码，用于测试日期对于二月份是否有效。测试leapYear是否为真或假的顶部部分工作正常。如果我输入例如02/29/1963作为日期，leapYear将= false。然而，由于某些原因，代码将继续执行，就好像leapYear = true一样。最终结果将是：
else if (leapYear = true){
if ((day > 0) && (day < 30) && (month ==2)){
System.out.println("Your date is valid.)"`它将输出“您的日期是有效的”。而它应该专门输出日期02/29/1963“您的日期无效，因为1963年的2月份只有28天。”)；
我不明白它为什么要这样做。耽误您时间，实在对不起。已解决
if ((year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0))) {
leapYear = true;
} else {
leapYear = false;
}
if (leapYear = false) {
if ((day > 0) && (day < 29) && (month == 2)) {
System.out.println("Your date is valid.");
} else if (day > 29) {
System.out.println("Your date is invalid because there are only 28 days in February"
+ "for the year " + year + ".");
} else {
System.out.println("Your date is invalid because the day you entered does not exist.");
}
} else if (leapYear = true) {
if ((day > 0) && (day < 30) && (month == 2)) {
System.out.println("Your date is valid.");
} else if (day > 30) {
System.out.println("Your date is invalid because there are only 29 days in February for"
+ "the year " + year + ".");
} else {
System.out.println("Your date is invalid because the day you entered does not exist.");
}
}
回答 4
Stack Overflow用户
发布于 2015-10-26 04:00:59
您的if和else-if条件不能为assignment操作，而应为comparison。
而不是if (leapYear = false){尝试
if (leapYear == false){或者只是
if (!leapYear){else if (leapYear = true){也是如此。它将是
else if (leapYear == true){或
else if (leapYear){Stack Overflow用户
发布于 2015-10-26 04:03:09
不能在if语句中使用赋值运算符。你必须做一个相等性检查：
if (leapYear == false) {
if ((day > 0) && (day < 29) && (month == 2)) {
System.out.println("Your date is valid.");
} else if (day > 29) {
System.out.println("Your date is invalid because there are only 28 days in February"
+ "for the year " + year + ".");
} else {
System.out.println("Your date is invalid because the day you entered does not exist.");
}
} else if (leapYear == true) {
if ((day > 0) && (day < 30) && (month == 2)) {
System.out.println("Your date is valid.");
} else if (day > 30) {
System.out.println("Your date is invalid because there are only 29 days in February for"
+ "the year " + year + ".");
} else {
System.out.println("Your date is invalid because the day you entered does not exist.");
}
}Stack Overflow用户
发布于 2015-10-26 05:53:38
我知道你不能在你的家庭作业中使用它，但仅供参考，Java在它的java.time框架中包含了这个特性。
ZonedDateTime now = ZonedDateTime.now ( ZoneId.of ( "America/Montreal" ) );
Year year = Year.from ( now );
Boolean isLeap = year.isLeap ();转储到控制台。
System.out.println ( "year: " + year + " isLeap: " + isLeap );运行时。
年份: 2015 isLeap: false
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原文链接：
https://stackoverflow.com/questions/33338247
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