[英]Java Compare single char to char array
我需要將單個char與char數組進行比較,看看array是否具有該char。
我當前的代碼如下所示:
public boolean isThereChar(char[] chaArray, String chr){
boolean bool = false;
for(int i=0; i < chaArray.length; i++)
{
if(chr.equals(chaArray[i])){
bool = true;
}
}
return bool;
}
編輯注釋:
真抱歉,造成混淆! 我只是Java初學者= /
基本上我是用GUI編寫小型Hangman游戲。
我的程序讀取了文本文件,並隨機選擇了玩家必須猜測的單詞,然后以隱藏方式將其打印出來,如下所示:_ _ _ _ _
在這種情況下,我希望玩家輸入字符或字符串(人們可以猜測整個單詞或僅一個字母)
然后,我希望我的程序采用該字母或字符串並與隱藏的單詞進行比較
以下代碼選擇單詞並將其隱藏:
public String pickWord(){
String guessWord = (wordsList[new Random().nextInt(wordsList.length)]);
return guessWord.toLowerCase();
}
//Hides picked word
public char[] setWord(){
char[] word = new char[pickWord().length() * 2];
for (int i = 0; i < word.length; i+=2) {
word[i] = '_';
word[i + 1] = ' ';
}
return word;
}
然后人輸入他想用以下代碼編程的字符:
public void actionPerformed(ActionEvent e) {
String action = e.getActionCommand();
if (action == "Guess Letter"){
inputChar = JOptionPane.showInputDialog("Please enter letter (a-z)");
if (inputChar.length() > 1){
GuessedLetters glr = new GuessedLetters(inputChar);
glr.setInString(inputChar);
//For testing purposes
System.out.println("This is String: " +glr.getInString());
}else{
GuessedLetters glr = new GuessedLetters(inputChar);
glr.setInChar(inputChar);
//For testing purposes
System.out.println("This is Char: " +glr.getInChar());
}
}
最后,我要輸入的字符與我隱藏的單詞字符數組進行比較:
public boolean isThereChar(char[] array, String str){
return isThereChar(array, str.charAt(0));
}
public boolean isThereChar(char[] array, char c){
for(int i=0; i<array.length; i++){
if (array[i] == c) return true;
}
return false;
}
我想檢查我的代碼返回什么(對或錯),但是我一直失敗。 (現在,我正在嘗試在主類中調用method進行檢查,如果可以給我提示如何做的話,否則請告訴我。)
我將使用: Chars.contains(array, chr);
與番石榴糖
之所以發生NullPointerException,是因為調用該方法時chaArray
或chr
為null
。 ( 如果不是,則NullPointerException發生在其他地方! )
您的代碼的另一個問題是這一行:
if (chr.equals(chaArray[i])) {
由於chr
實際上是一個String,因此這里將發生的是chaArray[i]
的值將自動裝箱為Character
對象,然后作為參數傳遞給String.equals(Object)
。 但是,除非String.equals(Object)
的參數為String
否則它將返回false
,因此您的代碼將始終找不到該字符。
您需要像這樣比較字符:
if (chr.charAt(0) == chaArray[i]) {
或將chr
聲明為char
並將其比較為:
if (chr == chaArray[i]) {
讓我們看看我是否滿足您的需求:
public void actionPerformed(ActionEvent e) {
String action = e.getActionCommand();
if (action == "Guess Letter"){
inputChar = JOptionPane.showInputDialog("Please enter letter (a-z)");
if (inputChar.length() > 1){ //User input is a string here, right?
GuessedLetters glr = new GuessedLetters(inputChar);
glr.setInString(inputChar);
System.out.println(wordToGuess.contains(glr.getInString())); //This will print true if wordToGuess is equal to glr.getInString() or if it just contains it
//For testing purposes
System.out.println("This is String: " +glr.getInString());
}else{ //Here the user gave us just a character, so we've got to know if this character is contained in the word, right?
GuessedLetters glr = new GuessedLetters(inputChar);
glr.setInChar(inputChar);
System.out.println(wordToGuess.contains(glr.getInChar()); //This will print true if your char is in the wordToGuess string
//For testing purposes
System.out.println("This is Char: " +glr.getInChar());
}
}
}
String chr
可能為null,從而導致NullPointerException
。
使用char chr
而不是String
。
public boolean isThereChar(char[] chaArray, char chr){
boolean bool = false;
for(int i=0; i < chaArray.length; i++) {
if(chr==chaArray[i])){
bool = true;
}
}
return bool;
}
從傳入的參數中選擇字符,或傳入一個字符,例如
chr[0]
要么
public String isThereChar(char[] chaArray, char chr){
for(int i=0; i < chaArray.length; i++)
{
if(chr.equals(chaArray[i])){
return chr;
}
}
return "Guess Again";
}
public boolean isThereChar(char[] chaArray, char chr){
for(int i=0; i < chaArray.length; i++)
{
if((chaArray[i]==chr)){
return true; // means Character exist in the Character array
}
}
return false; //// means Character does not exist in the Character array
}
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