Compare and Remove Same Characters in Two Strings in Java Then Output the Remaining Characters as Numbers

How to remove duplicate alphabets from two strings in java without any builtin functions?

Here is one approach,

// Write a static helper method.
public static boolean contains(char[] in, int index, char t) {
    for (int i = 0; i < index; i++) {
        if (in[i] == t) return true;
    }
    return false;
}

public static void main(String[] args) {
    String firstString = "google out"; // String(s) not String arrays
    String secondString = "stack overflow";
    // output cannot be larger then the sum of the inputs.
    char[] out = new char[firstString.length() + secondString.length()];
    int index = 0;
    // Add all unique chars from firstString
    for (char c : firstString.toCharArray()) {
        if (! contains(out, index, c)) {
            out[index++] = c;
        }
    }
    // Add all unique chars from secondString
    for (char c : secondString.toCharArray()) {
        if (! contains(out, index, c)) {
            out[index++] = c;
        }
    }
    // Create a correctly sized output array.
    char[] s = new char[index];
    for (int i = 0; i < index; i++) {
        s[i] = out[i];
    }
    // Just print it.
    System.out.println(Arrays.toString(s));
}

Output is

[g, o, l, e,  , u, t, s, a, c, k, v, r, f, w]

Edit

If your expected output is incorrect, and you actually want the characters that appear in both Strings.

public static void main(String[] args) {
    String firstString = "google out";
    String secondString = "stack overflow";
    char[] out = new char[firstString.length() + secondString.length()];
    int index = 0;
    for (char c : firstString.toCharArray()) {
        if (contains(secondString.toCharArray(), secondString.length(), c)) {
            out[index++] = c;
        }
    }
    char[] s = new char[index];
    for (int i = 0; i < index; i++) {
        s[i] = out[i];
    }
    System.out.println(Arrays.toString(s));
}

Which outputs

[o, o, l, e,  , o, t]

Edit 2

If you actually wanted the opposite of that, change the call to contains and add a second loop (for the inverse relationship) -

    for (char c : firstString.toCharArray()) {
        if (! contains(secondString.toCharArray(), secondString.length(), c)) {
            out[index++] = c;
        }
    }
    for (char c : secondString.toCharArray()) {
        if (! contains(firstString.toCharArray(), firstString.length(), c)) {
            out[index++] = c;
        }
    }

Which will then output

[g, g, u, s, a, c, k, v, r, f, w]

Removing duplicates from a String in Java

Convert the string to an array of char, and store it in a LinkedHashSet. That will preserve your ordering, and remove duplicates. Something like:

String string = "aabbccdefatafaz";

char[] chars = string.toCharArray();
Set<Character> charSet = new LinkedHashSet<Character>();
for (char c : chars) {
    charSet.add(c);
}

StringBuilder sb = new StringBuilder();
for (Character character : charSet) {
    sb.append(character);
}
System.out.println(sb.toString());

How to count common characters in two strings in JavaScript?

We can convert the second input string to an array, then the next step is to iterate over the first input string and find a match in the second input string's character array.

If a match is found, increment the counter and remove that character from the second input string's character array so that it is not considered in the next match:

//Solution:function getSameCount(str1, str2) {  let count = 0;  const obj = str2.split("");  for(str of str1){    let idx = obj.findIndex(s => s === str);    if(idx >= 0){      count++;      obj.splice(idx, 1);    }  }  return count;}
//Test:console.log(getSameCount("abcd", "aad"));console.log(getSameCount("geeksforgeeks", "platformforgeeks"));console.log(getSameCount("aad", "abcd"));console.log(getSameCount("platformforgeeks", "geeksforgeeks"));

StringBuilder sb = new StringBuilder(inputString);

String resultString = sb.toString();

public String method(String str) {
    if (str != null && str.length() > 0 && str.charAt(str.length() - 1) == 'x') {
        str = str.substring(0, str.length() - 1);
    }
    return str;
}

String str = "a12.334tyz.78x";
str = str.replaceAll("[^\\d.]", "");