Remove first and last character of a string in Java

Given string str, the task is to write Java Program to remove the first and the last character of the string and print the modified string.

Examples:

Input: str = “GeeksForGeeks”
Output: eeksForGeek
Explanation: The first character of the given string is ‘G’ and the last character of the given string is ‘s’. After removing the first and last character of a string, the string becomes “eeksForGeek”.

Input: str = “Java”
Output: av
Explanation: The first character of the given string is ‘J’ and the last character of the given string is ‘a’. After removing first and last character of a string, the string becomes “av”.

Method 1: Using String.substring() method

1. The idea is to use the substring() method of String class to remove first and the last character of a string.
2. The substring(int beginIndex, int endIndex) method accepts two parameters, first is starting index, and the second is ending index.
3. The first character of a string is present at index zero and the last character of a string is present at index length of string – 1.
4. Extract the substring excluding the first and last character using str.substring(1, str.length() – 1).
5. Now, print the modified string.

Below is the implementation of the above approach:

Java

// Java program to remove the first and
// the last character of a string

class GFG {

    // Function to remove the first and
    // the last character of a string
    public static String
    removeFirstandLast(String str)
    {

        // Removing first and last character
        // of a string using substring() method
        str = str.substring(1, str.length() - 1);

        // Return the modified string
        return str;
    }

    // Driver Code
    public static void main(String args[])
    {
        // Given String str
        String str = "GeeksForGeeks";

        // Print the modified string
        System.out.print(
            removeFirstandLast(str));
    }
}

Output:

eeksForGeek

Time Complexity: O(1)

Auxiliary Space: O(1)

Method 2: Using StringBuilder.deleteCharAt() method

1. The idea is to use the deleteCharAt() method of StringBuilder class to remove first and the last character of a string.
2. The deleteCharAt() method accepts a parameter as an index of the character you want to remove.
3. Remove last character of a string using sb.deleteCharAt(str.length() – 1).
4. Remove first character of a string using sb.deleteCharAt(0).
5. Now, print the modified string.

Below is the implementation of the above approach:

Java

// Java program to remove the first and
// the last character of a string

class GFG {

    // Function to remove the first and
    // the last character of a string
    public static String
    removeFirstandLast(String str)
    {

        // Creating a StringBuilder object
        StringBuilder sb = new StringBuilder(str);

        // Removing the last character
        // of a string
        sb.deleteCharAt(str.length() - 1);

        // Removing the first character
        // of a string
        sb.deleteCharAt(0);

        // Converting StringBuilder into a string
        // and return the modified string
        return sb.toString();
    }

    // Driver Code
    public static void main(String args[])
    {
        // Given String str
        String str = "GeeksForGeeks";

        // Print the modified string
        System.out.println(
            removeFirstandLast(str));
    }
}

Output:

eeksForGeek

Time Complexity: O(1)

Auxiliary Space: O(n) because it using for creating StringBuilder sb, where n is length of string

Method 3: Using StringBuffer.delete() method

1. The idea is to use the delete() method of StringBuffer class to remove first and the last character of a string.
2. The delete(start_point, int end_point) method accepts two parameters, first is start_point, and the second is end_point and it returns the string after deleting the substring formed by the range mentioned in the parameters.
3. Remove the last character of the string using sb.delete(str.length() – 1, str.length()).
4. Remove the first character of the string using sb.delete(0, 1).
5. Now, print the modified string.

Below is the implementation of the above approach:

Java

// Java program to remove the first and
// the last character of a string

class GFG {

    // Function to remove the first and
    // the last character of a string
    public static String
    removeFirstandLast(String str)
    {

        // Creating a StringBuffer object
        StringBuffer sb = new StringBuffer(str);

        // Removing the last character
        // of a string
        sb.delete(str.length() - 1, str.length());

        // Removing the first character
        // of a string
        sb.delete(0, 1);

        // Converting StringBuffer into
        // string & return modified string
        return sb.toString();
    }

    // Driver Code
    public static void main(String args[])
    {
        // Given String str
        String str = "GeeksForGeeks";

        // Print the modified string
        System.out.println(
            removeFirstandLast(str));
    }
}

Output:

eeksForGeek

Time Complexity: O(1)

Auxiliary Space: O(1)