Java string compareToIgnoreCase() Method

Posted in Java Tutorial

Updated on Jan 15, 2024

By Mari Selvan

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⏳ 4 mins

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Java string compareToIgnoreCase() Method

Photo Credit to CodeToFun

🙋 Introduction

In Java programming, manipulating strings is a common and fundamental task.

The compareToIgnoreCase() method is a member of the java.lang.String class and is used for comparing strings in a case-insensitive manner.

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

💡 Syntax

The method signature for compareToIgnoreCase() is as follows:

Syntax

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public int compareToIgnoreCase(String str)

This method compares the current string with another string (str) lexicographically, ignoring differences in case.

📄 Example

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

StringComparison.java

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public class StringComparison {
  public static void main(String[] args) {
    String str1 = "Hello, World!";
    String str2 = "HELLO, world!";

    // Compare strings lexicographically, ignoring case
    int result = str1.compareToIgnoreCase(str2);

    // Output the result
    if (result == 0) {
      System.out.println("The strings are equal.");
    } else if (result < 0) {
      System.out.println("str1 is lexicographically less than str2.");
    } else {
      System.out.println("str1 is lexicographically greater than str2.");
    }
  }
}

💻 Output

Output

The strings are equal.

🧠 How the Program Works

In this example, the compareToIgnoreCase() method compares the strings "Hello, World!" and "HELLO, world!" and prints the result.

↩️ Return Value

The compareToIgnoreCase() method returns an integer less than, equal to, or greater than zero, depending on whether the current string is lexicographically less than, equal to, or greater than the specified string.

📚 Common Use Cases

The compareToIgnoreCase() method is useful when you need to compare strings in a case-insensitive manner, such as when sorting strings or searching for a specific string regardless of case.

📝 Notes

The method uses the Unicode values of characters for comparison.
This method is particularly handy when you want to perform case-insensitive string comparisons without explicitly converting strings to lowercase or uppercase.

🎢 Optimization

The compareToIgnoreCase() method is optimized for case-insensitive string comparison. There is generally no need for further optimization unless specific performance requirements dictate a custom approach.

🎉 Conclusion

The compareToIgnoreCase() method in Java is a convenient tool for case-insensitive string comparison. It simplifies tasks involving lexicographic comparison while ignoring differences in case, contributing to cleaner and more readable code.

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