How to find the Characters in the First String that are not Present in the Second String in Java - Step by Step Examples

How to find the Characters in the First String that are not Present in the Second String in Java ?

Answer

To find the characters in the first string that are not present in the second string in Java, you can use a combination of loops and conditionals to filter out the characters.

✐ Examples

1 Find Unique Characters in First String

In this example,

We create two string variables named str1 and str2 with different values.
We convert str2 to a set of characters to allow for quick look-up of characters.
We initialize a StringBuilder to build the resulting string containing characters present in str1 but not in str2.
We iterate over each character in str1, and for each character, we check if it is not present in the set of characters of str2.
If the character is not present in str2, we append it to the StringBuilder.
Finally, we print the resulting string to standard output.

Java Program

import java.util.HashSet;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
        String str1 = "abcdef";
        String str2 = "bdf";
        Set<Character> charSet = new HashSet<>();
        for (char c : str2.toCharArray()) {
            charSet.add(c);
        }
        StringBuilder result = new StringBuilder();
        for (char c : str1.toCharArray()) {
            if (!charSet.contains(c)) {
                result.append(c);
            }
        }
        System.out.println("Characters in str1 not in str2: " + result.toString());
    }
}

Output

Characters in str1 not in str2: ace

2 Find Unique Characters in Another Pair of Strings

In this example,

We create two string variables named str1 and str2 with different values.
We convert str2 to a set of characters to allow for quick look-up of characters.
We initialize a StringBuilder to build the resulting string containing characters present in str1 but not in str2.
We iterate over each character in str1, and for each character, we check if it is not present in the set of characters of str2.
If the character is not present in str2, we append it to the StringBuilder.
Finally, we print the resulting string to standard output.

Java Program

import java.util.HashSet;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
        String str1 = "hello world";
        String str2 = "world";
        Set<Character> charSet = new HashSet<>();
        for (char c : str2.toCharArray()) {
            charSet.add(c);
        }
        StringBuilder result = new StringBuilder();
        for (char c : str1.toCharArray()) {
            if (!charSet.contains(c)) {
                result.append(c);
            }
        }
        System.out.println("Characters in str1 not in str2: " + result.toString());
    }
}

Output

Characters in str1 not in str2: he

Summary

In this tutorial, we learned How to find the Characters in the First String that are not Present in the Second String in Java language with well detailed examples.

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How to find the Characters in the First String that are not Present in the Second String in Java - Step by Step Examples

How to find the Characters in the First String that are not Present in the Second String in Java ?

Answer

✐ Examples

1 Find Unique Characters in First String

Java Program

Output

2 Find Unique Characters in Another Pair of Strings

Java Program

Output

Summary

More Java Strings Tutorials