Given a String, the task is to convert the string into an Array of Strings in Java. It is illustrated in the below illustration which is as follows:
Illustration:
Input: String : "Geeks for Geeks" Output: String[]: [Geeks for Geeks]
Input: String : "A computer science portal" Output: String[] : [A computer science portal]
Methods:
They are as follows:
- Using str.split() method
- Using loops
- Using Set.toArray() method
- Using String tokenizer
- Using pattern.split() method
Lets us now discuss every method in depth implementing the same to get a better understanding of the same. They are as follows:
Method 1: Using str.split() method
Approach:
- Create an array with string type.
- Split the given string using string_name.split().
- Store splitted array into string array.
- Print the above string array.
Example
Java
// Java Program to Convert String to String Array// Using str.split() method// Importing input output classesimport java.io.*;// Main classpublic class GFG { // Main driver method public static void main(String[] args) { // Input string to be convert to string array String str = "Geeks for Geeks"; String strArray[] = str.split(" "); System.out.println("String : " + str); System.out.println("String array : [ "); // Iterating over the string for (int i = 0; i < strArray.length; i++) { // Printing the elements of String array System.out.print(strArray[i] + ", "); } System.out.print("]"); }} |
Output
String : Geeks for Geeks String array : [ Geeks, for, Geeks, ]
Method 2: Using loops
Approach:
- Get the set of strings.
- Create an empty string array
- Use advanced for loop, copy each element of set to the string array
- Print the string array.
Example:
Java
// Java Program to Convert String to String Array// Using HashSet and Set classes// Importing required classes from respective packagesimport java.io.*;import java.util.Arrays;import java.util.HashSet;import java.util.Set;// Main classclass GFG { // Method 1 // To convert Set<String> to String[] public static String[] method(Set<String> string) { // Create String[] of size of setOfString String[] string_array = new String[string.size()]; // Copy elements from set to string array // using advanced for loop int index = 0; for (String str : string) { string_array[index++] = str; } // Return the formed String[] return string_array; } // Method 2 // Main driver method public static void main(String[] args) { // Custom input string String str = "Geeks for Geeks"; // Getting the Set of String Set<String> string_set = new HashSet<>(Arrays.asList(str)); // Printing the setOfString System.out.println("String: " + str); // Converting Set to String array String[] String_array = method(string_set); // Lastly printing the arrayOfString // using Arrays.toString() method System.out.println("Array of String: " + Arrays.toString(String_array)); }} |
Output
String: Geeks for Geeks Array of String: [Geeks for Geeks]
Method 3: Using Set.toArray() method
Approach:
- Convert the given string into set of string.
- Now create an empty string array.
- Convert the string set to Array of string using set.toArray() by passing an empty array of type string.
- Print the array of string.
Example:
Java
// Java Program to Convert String to String Array// Using Set.toArray() method// Importing required classes from respective packagesimport java.io.*;import java.util.Arrays;import java.util.HashSet;import java.util.Set;// Main classpublic class GFG { // Method 1 // To convert Set<String> to string array public static String[] convert(Set<String> setOfString) { // Create String[] from setOfString String[] arrayOfString = setOfString.toArray(new String[0]); // return the formed String[] return arrayOfString; } // Method 2 // Main driver method public static void main(String[] args) { // Custom input string as input String str = "Geeks for Geeks"; // Getting the Set of String Set<String> string = new HashSet<>(Arrays.asList(str)); // Printing the setOfString System.out.println("String: " + str); // Converting Set to String array String[] string_array = convert(string); // Print the arrayOfString // using Arrays.toString() method System.out.println("String array : " + Arrays.toString(string_array)); }} |
Output
String: Geeks for Geeks String array : [Geeks for Geeks]
Method 4: Using String tokenizer
String tokenizer helps to split a string object into smaller and smaller parts. These smaller parts are known as tokens.
- Tokenize the given string
- Create an array of type string with the size of token counts.
- Store these tokens into a string array.
- Print the string array.
Example:
Java
// Java Program to Convert String to String Array// Using Set.toArray() method// Importing required classes from respective packagesimport java.io.*;import java.util.StringTokenizer;// Main classpublic class GFG { // Main driver method public static void main(String[] args) { // Declaring and initializing integer variable // to zero int i = 0; // Custom input string as input String str = "Geeks for Geeks"; // Tokenize a given string using the default // delimiter StringTokenizer str_tokenizer = new StringTokenizer(str); String[] string_array = new String[str_tokenizer.countTokens()]; // Add tokens to our array while (str_tokenizer.hasMoreTokens()) { string_array[i] = str_tokenizer.nextToken(); i++; } // Print and display the string System.out.print("String :" + str); // Display message System.out.print("\nString array : [ "); // Printing the string array // using for each loop for (String string : string_array) { System.out.print(string + " "); } System.out.print("]"); }} |
Output
String :Geeks for Geeks String array : [ Geeks for Geeks ]
Method 5: Using pattern.split() method
The purpose of this pattern.split() method is to break the given string into an array according to a given pattern. We can split our string by giving some specific pattern.
Approach:
- Define pattern (REGEX)
- Then create a pattern using the compilation method
- Then split the string using pattern.split() with a specific pattern and store it in the array.
- Print the string array
Example:
Java
// Java Program to Convert String to String Array// Using Set.toArray() method// Importing required classes from respective packagesimport java.io.*;import java.util.regex.Pattern;// Main classpublic class GFG { // Main driver method public static void main(String[] args) { // Custom string as input String str = "Geeks for Geeks"; // Step 1: Define REGEX String my_pattern = "\\s"; // Step 2: Create a pattern using compile method Pattern pattern = Pattern.compile(my_pattern); // Step 3: Create an array of strings using the // pattern we already defined String[] string_array = pattern.split(str); // Print and display string and // its corresponding string array System.out.print("String : " + str); System.out.print("\nString array : [ "); // Iterating over the string for (int i = 0; i < string_array.length; i++) { // Printing the string array System.out.print(string_array[i] + " "); } System.out.print("]"); }} |
Output
String : Geeks for Geeks String array : [ Geeks for Geeks ]
