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() Method
Method 1: Using searching techniques
- 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 techniques// Importing input output classesimport java.io.*;// main classclass GFG { // 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 = ""; // Iterating the string using for each loop for (String words : msg) { // If desired word is found if (!words.equals(word)) { // Concat the word not equal to the given // word new_str += words + " "; } } // Print the new String System.out.print(new_str); } // Method 2 // Main driver method public static void main(String[] args) { // Custom string as input String str = "This is the Geeks For Geeks"; // Word to be removed from above string String word = "the"; // 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() Method
- 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.
Example
Java
// Java Program to Remove a Given Word From a String// Importing input output classesimport java.io.*;// Main classclass GFG { // 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"; // Desired word to be removed String word = "the"; // Replace all words by "" string // using replaceAll() method str = str.replaceAll("the", ""); // Trim the string using trim() method str = str.trim(); // Printing the final string System.out.print(str); }} |
Output
This is Geeks For Geeks
Time Complexity: O(n)
Auxiliary Space: O(n)
