Question

我正在研究一个问题，我必须计算文本中的字符频率。我有一段时间没有编码而且有点生疏，所以我认为这对我的代码第二双眼睛有帮助。我的代码读入一个文件，理想情况下它应该命中我的if语句并将“1”加到我的频率数组中。但是，它始终打印“0”。我没有正确添加吗？

public class hw4{
public static void main (String []args)throws IOException{

//ask user to enter file name
System.out.printf("Enter a file location and name to encode [press Enter]: ");

Scanner input = new Scanner(System.in);
String filename = input.next();

//Gets file name from Scanner and checks to see if valid
File file = new File(filename);
Scanner text = new Scanner(file);

String[] letters = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
int[] freq = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

String letter;

    while(text.hasNext()){
        letter = text.next();

        if (letter == "a"){
        freq[0] = freq[0] + 1;
        }
        if (letter == "b"){
        freq[1] = freq[1] + 1;
        }
        if (letter == "c"){
        freq[2] = freq[2] + 1;
        }
        if (letter == "d"){
        freq[3] = freq[3] + 1;
        }
        if (letter == "e"){
        freq[4] = freq[4] + 1;
        }
        if (letter == "f"){
        freq[5] = freq[5] + 1;
        }
        if (letter == "g"){
        freq[6] = freq[6] + 1;
        }
        if (letter == "h"){
        freq[7] = freq[7] + 1;
        }
        if (letter == "i"){
        freq[8] = freq[8] + 1;
        }
        if (letter == "j"){
        freq[9] = freq[9] + 1;
        }
        if (letter == "k"){
        freq[10] = freq[10] + 1;
        }
        if (letter == "l"){
        freq[11] = freq[11] + 1;
        }
        if (letter == "m"){
        freq[12] = freq[12] + 1;
        }
        if (letter == "n"){
        freq[13] = freq[13] + 1;
        }
        if (letter == "o"){
        freq[14] = freq[14] + 1;
        }
        if (letter == "p"){
        freq[15] = freq[15] + 1;
        }
        if (letter == "q"){
        freq[16] = freq[16] + 1;
        }
        if (letter == "r"){
        freq[17] = freq[17] + 1;
        }
        if (letter == "s"){
        freq[18] = freq[18] + 1;
        }
        if (letter == "t"){
        freq[19] = freq[19] + 1;
        }
        if (letter == "u"){
        freq[20] = freq[20] + 1;
        }
        if (letter == "v"){
        freq[21] = freq[21] + 1;
        }
        if (letter == "w"){
        freq[22] = freq[22] + 1;
        }
        if (letter == "x"){
        freq[23] = freq[23] + 1;
        }
        if (letter == "y"){
        freq[24] = freq[24] + 1;
        }
        if (letter == "z"){
        freq[25] = freq[25] + 1;
        }
    }

    for(int i=0; i <26; i++){
    System.out.printf("%s:%d\n", letters[i], freq[i]);
    }
}

}

Answer 1

我意识到存在等效性问题。

检查不是

if（letter ==“a”）

但是

如果（letter.equals（ “A”）

使用整数添加数组索引

1 个答案: