Java string codePointCount() Method

Posted in Java Tutorial

Updated on Jan 15, 2024

By Mari Selvan

👁️ 64 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In Java programming, the String class provides various methods for manipulating and analyzing strings.

The codePointCount() method is one such method that calculates the number of Unicode code points in a specified range of a string.

In this tutorial, we'll explore the usage and functionality of the codePointCount() method in Java.

💡 Syntax

The signature of the codePointCount() method is as follows:

Syntax

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public int codePointCount(int beginIndex, int endIndex)

beginIndex: The index to start counting code points from (inclusive).
endIndex: The index to stop counting code points at (exclusive).

📄 Example

Let's dive into an example to illustrate how the codePointCount() method works.

CodePointCountExample.java

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public class CodePointCountExample {
  public static void main(String[] args) {
    String str = "Java\uD83D\uDE80Programming";

    // Count code points from index 0 to the end
    int count1 = str.codePointCount(0, str.length());
    System.out.println("Code points count (entire string): " + count1);

    // Count code points from index 5 to the end
    int count2 = str.codePointCount(5, str.length());
    System.out.println("Code points count (substring from index 5): " + count2);
  }
}

💻 Output

Output

Code points count (entire string): 16
Code points count (substring from index 5): 12

🧠 How the Program Works

In this example, the codePointCount() method is used to count the number of Unicode code points in different ranges of the string "Java\uD83D\uDE80Programming."

↩️ Return Value

The codePointCount() method returns the number of Unicode code points in the specified range.

📚 Common Use Cases

The codePointCount() method is useful when you need to deal with characters that are represented by multiple code points, such as emoji or certain accented characters. It provides an accurate count of code points, which is essential for correct string manipulation.

📝 Notes

The beginIndex and endIndex parameters specify a range within the string. The count includes the code point at the beginIndex and excludes the code point at the endIndex.
Be aware that characters represented by surrogate pairs (such as some emoji) contribute to the count as a single code point.

🎢 Optimization

The codePointCount() method is optimized for accurate counting of Unicode code points. Ensure that you correctly specify the range to achieve the desired results.

🎉 Conclusion

The codePointCount() method in Java is a valuable tool when dealing with strings that include characters represented by multiple code points. It enhances the precision of code point counting and contributes to the overall robustness of string manipulation in Java.

Feel free to experiment with different strings and explore the behavior of the codePointCount() method in various scenarios. Happy coding!