Need a little help with a function!

[Nuluvius]

Hi,

I'v got a slight problem, Im sure its quite simple to solve - I just dont know how to order the syntax :/

I have to solve the following problem:

Design, code and test a function:

public static boolean contains(String str1,String str2)
// pre: str1 and str2 not null
// post: returns true if str2 is a substring of str1.

Hint: you will need a loop, and will need to know the length of str1 and str2.

For the solution I have so far worked out that I need to make use of the Pattern and Matcher methods to determin if str2 (in its entirity) exists anywhere within str1. Any assistance would be greatly apprechiated!

[tim]

Welcome, Nuluvius, to Java Forums

There is a very easy solution for your problem. You can use the String.indexOf() method to determine if a String is a substring of another. I did this:

Code:

public static boolean contains(String string1, String string2){
	return -1 != string1.indexOf(string2);
}

In my testing class, I had:

Code:

package pack;
import java.util.*;
public class Test{
	public Test(){
		System.out.println("Test running");
		System.out.println("Enter string1:");
		String string1 = Tools.readln();
		System.out.println("Enter string2:");
		String string2 = Tools.readln();
		System.out.println("Result = " + contains(string1, string2));
	}
	public static boolean contains(String string1, String string2){
		return -1 != string1.indexOf(string2);
	}
}

output:

Code:

Test running
Enter string1:
true love
Enter string2:
love
Result = true

I hope this helps you.

[Nuluvius]

Firstly, thank you for the welcome!

Secondly, that is amazing, I had actualy spent about 2/3 hours on this particular problem.. yet it was so simple. Thank you very much for sloving it and putting me out of my angush.

I think it goes without saying that I am only just learning java lol. This is my first year of a Software Engineering degree. I shal definatly be returning with my future conundrems

[tim]

I'm glad to help Nuluvius. I am currently studying a B.Sc. in Computer Science and I believe that your instructor either wants you to formulate an algorithm for this problem or use regular expressions. Anyway, good luck!