Which of these methods is used to compare a specific region inside a string with another specific region in another string?

The Java Tutorials have been written for JDK 8. Examples and practices described in this page don't take advantage of improvements introduced in later releases and might use technology no longer available.
See Java Language Changes for a summary of updated language features in Java SE 9 and subsequent releases.
See JDK Release Notes for information about new features, enhancements, and removed or deprecated options for all JDK releases.

The String class has a number of methods for comparing strings and portions of strings. The following table lists these methods.

The following program, RegionMatchesDemo, uses the regionMatches method to search for a string within another string:

public class RegionMatchesDemo { public static void main(String[] args) { String searchMe = "Green Eggs and Ham"; String findMe = "Eggs"; int searchMeLength = searchMe.length(); int findMeLength = findMe.length(); boolean foundIt = false; for (int i = 0; i <= (searchMeLength - findMeLength); i++) { if (searchMe.regionMatches(i, findMe, 0, findMeLength)) { foundIt = true; System.out.println(searchMe.substring(i, i + findMeLength)); break; } } if (!foundIt) System.out.println("No match found."); } }

The output from this program is Eggs.

The program steps through the string referred to by searchMe one character at a time. For each character, the program calls the regionMatches method to determine whether the substring beginning with the current character matches the string the program is looking for.

This method has two variants which can be used to test if two string regions are equal.

Syntax

Here is the syntax of this method −

Parameters

Here is the detail of parameters −

• toffset − the starting offset of the subregion in this string.

• other − the string argument.

• ooffset − the starting offset of the subregion in the string argument.

• len − the number of characters to compare.

Return Value

• It returns true if the specified subregion of this string matches the specified subregion of the string argument; false otherwise. Whether the matching is exact or case insensitive depends on the ignoreCase argument.

Example

This will produce the following result −

Output

java_strings.htm

Home » JAVA Programming » Strings » Question

1. Which of these methods is used to compare a specific region inside a string with another specific region in another string?

1. 1. regionMatches()
   2. regionMatch()
   3. match()
   4. RegionMatches()
   5. None of these

regionMatches()

Improve Article

Save Article

Like Article

The regionMatches() method of the String class has two variants that can be used to test if two string regions are matching or equal. There are two variants of this method, i.e., one is case sensitive test method, and the other ignores the case-sensitive method.

Syntax:

1. Case sensitive test method:

2. It has the option to consider or ignore the case method:

Parameters:

• ignoreCase: if true, ignore the case when comparing characters.
• toffset: the starting offset of the subregion in this string.
• other: the string argument being compared.
• offset: the starting offset of the subregion in the string argument.
• len: the number of characters to compare.

Return Value:

A substring of the String object is compared to a substring of the argument other. The result is true if these substrings represent character sequences that are the same, ignoring case if and only if ignoreCase is true. The substring of this String object to be compared begins at index toffset and has length len. The substring of other to be compared begins at index offset and has length len. The result is false if and only if at least one of the following is true

Example 1:

OutputResult of Comparing of String 1 and String 2: true Result of Comparing of String 1 and String 3: false Result of Comparing of String 2 and String 3: false

Example 2:

OutputResult of comparing String 1 and String 2 : true Result of comparing String 1 and String 3 : false Result of comparing String 2 and String 3 : true

Note: The method returns false if at least one of these is true,

• toffset is negative.
• offset is negative.
• toffset+len is greater than the length of this String object.
• ooffset+len is greater than the length of the other argument.
• ignoreCase is false, and there is some nonnegative integer k less than len such that:

• ignoreCase is true, and there is some nonnegative integer k less than len such that: