How to Compare Strings in Java Without Case Sensitivity: A Complete Guide with Examples

To compare two strings without considering case sensitivity in Java, you can use the following approaches:

1. Using equalsIgnoreCase()

The String class in Java provides the method equalsIgnoreCase() to compare two strings without considering case.

Example:

public class StringComparisonExample {
    public static void main(String[] args) {
        String str1 = "Hello";
        String str2 = "hello";

        if (str1.equalsIgnoreCase(str2)) {
            System.out.println("The strings are equal (case-insensitive).");
        } else {
            System.out.println("The strings are not equal.");
        }
    }
}

Output:

The strings are equal (case-insensitive).

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2. Using toLowerCase() or toUpperCase()

You can convert both strings to the same case (e.g., lower or upper) before comparing them using equals().

Example:

public class StringComparisonExample {
    public static void main(String[] args) {
        String str1 = "Hello";
        String str2 = "hello";

        if (str1.toLowerCase().equals(str2.toLowerCase())) {
            System.out.println("The strings are equal (case-insensitive).");
        } else {
            System.out.println("The strings are not equal.");
        }
    }
}

Output:

The strings are equal (case-insensitive).

---

3. Using compareToIgnoreCase()

The compareToIgnoreCase() method compares two strings lexicographically, ignoring case differences.

Example:

public class StringComparisonExample {
    public static void main(String[] args) {
        String str1 = "Hello";
        String str2 = "hello";

        if (str1.compareToIgnoreCase(str2) == 0) {
            System.out.println("The strings are equal (case-insensitive).");
        } else {
            System.out.println("The strings are not equal.");
        }
    }
}

Output:

The strings are equal (case-insensitive).

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Key Points:

• Use equalsIgnoreCase() for a straightforward case-insensitive comparison.
• toLowerCase() or toUpperCase() allows you to manipulate and compare strings more flexibly.
• compareToIgnoreCase() is useful for sorting or lexicographical comparison.