String to find A character

Question

I want to find(A characters) in a string. if there is one A character, then specific operation is done and if there is two AA in string then other specific operation is done. How can i find out the string have how many A characters?

Answer 1

1. If you're beginner check this :

   String s1=" read the documentation for the methods of String"; //your string
   char ch=s1.charAt(s1.indexOf('A'));  //first appearance of character A
   int count = 0; 
   for(int i=0;i<s1.length();i++) { 
       if(s1.charAt(i)=='A'){ //if character at index i equals to 'A'
           System.out.println("number of A:=="+ch);
           count++; //increment count
       }
   }
   System.out.println("Total count of A:=="+count);
   

2. If you're not beginner:

    String s="Good , I think so";
    int counter = s.split("A").length - 1;  //you can change A with your character
   

Answer 2

You didn't state if you are checking for 2 AAs and only 2 AAs. If the question is "more than one A", then:

String s1=" read the documentation for the methods of String";
if(s1.replaceAll("A","").length() < s1.length()-1){
      //this string has more than one "A"
}

Answer 3

Iterate through every character in the string and test the character each time:

String s = "foo bAr";
int count = 0;

for (int i = 0; i < s.length(); i++) {
    if (s.charAt(i) == 'A') {
        count++;
    }
}

Then count would be the number of As found in the string.

Answer 4

String s = "some number of A characters in this AA string";
System.out.println(s.length() - s.replaceAll("A","").length());

Result:

3