Given a string and a word that task to remove the word from the string if it exists otherwise return -1 as an output. For more clarity go through the illustration given below as follows.
Illustration:
Input : This is the Geeks For Geeks
word="the"
Output : This is Geeks For Geeks
Input : Hello world Hello"
word = Hello
Output : world
Explanation: The given string contains the word two times
Input : Hello world
word = GFG
Output : Hello world
Explanation: word doesn't exists in the string
Now in order to reach the goal, we will be discussing ou two approaches namely as follows:
- Naive approach using searching techniques
- Optimal approach using String.replaceAll() MethodÂ
Method 1: Using searching techniquesÂ
- Convert the string into a string array.
- Iterate the array and check the word not equal to the given word.
- Concatenate the word into a new string array name as a new string.
- Print the new string.
Example
Java
// Java Program to Remove a Given Word From a String// using searching techniquesÂ
// Importing input output classesimport java.io.*;Â
// main classclass GFG {Â
    // Method 1    // To remove the word    static void remove(String str, String word)    {        // Split the string using split() method        String msg[] = str.split(" ");        String new_str = "";Â
        // Iterating the string using for each loop        for (String words : msg) {Â
            // If desired word is found            if (!words.equals(word)) {Â
                // Concat the word not equal to the given                // word                new_str += words + " ";            }        }Â
        // Print the new String        System.out.print(new_str);    }Â
    // Method 2    // Main driver method    public static void main(String[] args)    {        // Custom string as input        String str = "This is the Geeks For Geeks";Â
        // Word to be removed from above string        String word = "the";Â
        // Calling the method 1 by passing both strings to        // it        remove(str, word);    }} |
Output
This is Geeks For Geeks
Time Complexity: O(n), where n is the length of the given string.
Auxiliary Space: O(n), where n is the length of the given string
Method 2: Using String.replaceAll() MethodÂ
- This method takes two input old_word and the new word in the regex format.
- Replace all the old_word with the new word.
- Returns the resultant string.
ExampleÂ
Java
// Java Program to Remove a Given Word From a StringÂ
// Importing input output classesimport java.io.*;Â
// Main classclass GFG {Â
    // Main driver method    public static void main(String[] args)    {        // Given String as input from which        // word has to be removed        String str = "This is the Geeks For Geeks";Â
        // Desired word to be removed        String word = "the";Â
        // Replace all words by "" string        // using replaceAll() method        str = str.replaceAll("the", "");Â
        // Trim the string using trim() method        str = str.trim();Â
        // Printing the final string        System.out.print(str);    }} |
Output
This is Geeks For Geeks
Time Complexity: O(n)
Auxiliary Space: O(n)
