Split a string without built-in functions in Java

In this article, we are going to see how to split a string manually without using any in-built function. To split a string, we need an input string and a delimiter. A delimiter is a character on which the string needs to be split.

Example :

Input :
String: W3Colleges is a wonderful portal.
Delimiter: ” ” (Space)
Output :
W3Colleges
is
a
wonderful
portal.

Approach :

1. The characters of the string have to be read one by one and kept appending in a temporary string until a delimiter is read.
2. When the delimiter is read, print the temporary string. Re-initialize the temporary string to empty string.
3. There is one more case to be handled which is if the character read is the last character, but it is not the delimiter.
4. Like in the previous example where the delimiter was a space (” “), the end of the sentence contained a “.” which was not the delimiter.
5. Since it was the last character of the string, the temporary string needs to be printed as it as.

Implementation :

class Main {
    public static void printWords(String text, char delimiter)
    {
        // Temporary string
        String word = "";
        for (int i = 0; i < text.length(); i++) {
            // Read the current character
            char ch = text.charAt(i);
            
           // If the character is delimiter, print the word
            if (ch == delimiter) {
                System.out.println(word);
                word = "";
            }
            // If its the end of string, print the word
            else if (i == text.length() - 1 && ch != delimiter) {
                word += ch;
                System.out.println(word);
            }
            // Add characters to word
            else {
                word += ch;
            }
        }
    }

    public static void main(String[] args) throws java.lang.Exception
    {
        printWords("W3Colleges is a wonderful portal.", ' ');
    }
}

W3Colleges
is
a
wonderful
portal.