尝试在字符串中查找计数

Question

String at = "123123";
        for (int i = 0; i <at.length() ; i++) {
            if (at.charAt(i)==1){
                int count=0;
                count++;
            }
        }

想要1出现2次。哪里我的失败。谢谢。

Answer 1

String at = "123123";
int count = 0; // Move out
for (int i = 0; i < at.length(); i++) {
  if (at.charAt(i) == '1'){ // Compare with the char '1'
    count++;
  }
}
// count is 2 here.

Answer 2

    String at = "123123";
    int count = 0;//outside the loop
    int oneDigitCount = 0;
    for (int i = 0; i < at.length(); i++) {
        if (Character.isDigit(at.charAt(i))) {//digit count
            count++;
        }
        if(at.charAt(i)=='1'){//count ones in string
            oneDigitCount++; 
        }
    }