從句子中刪除一個字符

Question

我正在寫一個從程序中刪除一個字符的java程序。我得到一個錯誤，說：方法charAt（int）是未定義的類型java.Lang.String。 [line 35]

任何建議這意味着什麼。

public class Ex1Program { 

public void start() { 

String sentence = getSentenceFromUser(); 
int randomPosition = getRandomPosition(sentence); 
printCharacterToBeRemoved(sentence, randomPosition); 
String changedSentence = removeCharacter(sentence, randomPosition); 
printNewSentence(changedSentence); 

} 

private String getSentenceFromUser() { 
System.out.print("Enter a sentence :"); 
String sentence = Keyboard.readInput(); 
return sentence; 
} 
private int getRandomPosition(String sentence) { 
int randomPosition = (int)(Math.random() * 14) +1; 
return randomPosition; 
} 

private void printCharacterToBeRemoved(String sentence, int randomPosition) { 
System.out.print("Removing " + sentence.charAt(randomPosition) + " from position " +     randomPosition); 

} 

private String removeCharacter(String sentence, int randomPosition) { 
String changedSentence = sentence.trim().CharAt(randomPosition); 
return changedSentence; 
} 

private void printNewSentence(String changedSentence) { 
System.out.print("New sentence is " + changedSentence); 
} 
} 

Answer 1

String changedSentence = sentence.trim().CharAt(randomPosition); 

這charAt不CharAt。儘管如此，如果你做了這個改變，你仍然試圖將一個char分配給一個應該保持String的變量。您可以使用Character.toString將字符轉換爲字符串。

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P.S.如果要刪除字符串中的字符，請使用StringBuilder：

String changedSentence = (new StringBuilder(sentence)). 
             deleteCharAt(randomPosition).toString()