![isPalindrome]( "isPalindrome")
本文介绍了局部变量未使用的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我试图测试一个输入的单词是否是回文（相同的拼写正向和反向）。从我可以看到它应该工作，但Eclipse说局部变量isPalindrome的值不被使用，但它被使用。问题是，即使这个词不是一个回文，它说是这样的。
import java.util.Scanner;
public class Palindrome {
public static void main（String [] args）{
String phrase;
char [] phraseLetters;
int endChar;
boolean isPalindrome;
扫描仪输入=新的扫描仪（System.in）;
System.out.println（输入单词或短语）;
phrase = input.nextLine（）;
input.close（）;
phrase = phrase.toLowerCase（）;
phrase = phrase.replaceAll（，）;
phraseLetters = phrase.toCharArray（）;
endChar = phraseLetters.length - 1; （int i = 0; i< phraseLetters.length; i ++）{
if（phraseLetters [i]！= phraseLetters [endChar]）{
isPalindrome = false ;
} else {
isPalindrome = true;
endChar - = 1;
}
}
if（isPalindrome = true）{
System.out.println（输入的这个单词或短语是一个回文）;
} else {
System.out.println（这个词或短语不是回文）;
}
}
}
编辑：我尝试过if（isPalindrome == true）
和
if（isPalindrome）
在这两种情况下，Eclipse说本地变量isPalindrome可能未被初始化，在此if条件中。
FINAL EDIT：
我已经移动了，并重写了这段代码，但是如果还有人仍然修改了我的原始代码看看这个。
我在代码开头初始化了isPalindrome：
Boolean isPalinddrome = True;
我将for循环条件更改为：
for（int i = 0;（i< phraseLetters.length）&&（isPalindrome）; i ++）
$ b $如果（isPalindrome = true）到 if（isPalindrome）
应该是 if（isPalindrome == true），则div class =h2_lin>解决方案 （或 if（isPalindrome） 更好！实际上这个错误是另一个很好的理由，为什么不问，如果 someBoolean == true 这是一个坏的风格）
By键入 if（isPalindrome = true）您再次将值 true 分配给变量 isPalindrome 。而且由于你只是为它赋值，所以编译器会向你发出关于未使用的变量的警告。
这也是很好的： p>
所以，当你执行 if（isPalindrome = true）然后if条件总是满足
I am trying to make a test of whether an inputted word is a palindrome or not (the same spelled forward and backward). From what I can see it should work but Eclipse says "The value of the local variable isPalindrome is not used" , but it is used. The problem is that even if the word is not a palindrome it says it is.
import java.util.Scanner;
public class Palindrome {
public static void main(String[] args) {
String phrase;
char[] phraseLetters;
int endChar;
boolean isPalindrome;
Scanner input = new Scanner(System.in);
System.out.println("Enter a word or phrase.");
phrase = input.nextLine();
input.close();
phrase = phrase.toLowerCase();
phrase = phrase.replaceAll(" ","");
phraseLetters = phrase.toCharArray();
endChar = phraseLetters.length - 1;
for (int i = 0; i < phraseLetters.length; i++) {
if (phraseLetters[i] != phraseLetters[endChar]) {
isPalindrome = false;
} else {
isPalindrome = true;
endChar -= 1;
}
}
if (isPalindrome = true) {
System.out.println("This word or phrase entered is a palindrome.");
} else {
System.out.println("This word or phrase is not a palindrome.");
}
}
}
EDIT: I have tried the if statement being
if (isPalindrome == true)
and
if (isPalindrome)
In both cases Eclipse says "The local variable isPalindrome may not have been initialized," in this if condition.
FINAL EDIT:
I have since moved on, and rewritten this code, however I just went back and fixed my original code if anyone still looks at this.
I initialized isPalindrome at the beginning of the code:
Boolean isPalinddrome = True;
I changed the for-loop condition to:
for (int i = 0; (i < phraseLetters.length) && (isPalindrome); i++)
Finally I changed if (isPalindrome = true) to if (isPalindrome)
解决方案
if (isPalindrome = true) should be if (isPalindrome == true) (or if (isPalindrome) better! Actually this error is another good reason why not asking if someBoolean == true which is a bad style)
By typing if (isPalindrome = true) you're assigning, again, the value true to the variable isPalindrome. And since you're only assigning value to it, the compiler warns you about unused variable.
It's also good to know this:
So, when you do if (isPalindrome = true) then the if condition is always satisfied.
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