String Index - sub string and main string Something is not working properly

Question

I want the sub-array array has been tested in main array. but i get error.

The test I'm doing is right or need to add more conditions?

Finally, I need to print the index of the main array, in which sub-string begins.

Example to answer:

String m="cd e";
String n="abcd efghi";

print>>>> 2(the index in n String)

the error:

 Exception in thread "main" java.lang.StringIndexOutOfBoundsException:         
 String  index out of range: 4
 at java.lang.String.charAt(Unknown Source)
 at test1.main(test1.java:10)

The code:

    String m="cd e";
    String n="abcd efghi";


    for (int i = 0; i < m.length(); i++) {
        for (int j = 0; j < n.length(); j++) {
            if(m.charAt(j)==n.charAt(i) )
                if(m.charAt(j+1)==n.charAt(i+1))
                    System.out.println(i);          
        }   
     }

thank's.

change 'm.length()' to 'm.length() - 1' in the loops and what do you think j+1 will do if you are testing last item? — HRgiger
– HRgiger, Commented Jun 6, 2016 at 14:00
Few hints: (1) your i seems to be iterator for m and j for n, so why are you using i for n? (you should name your variables more reasonably, even i1 i2 n1 n2 would cause less confusion). (2) what value will i+1 have when i will be equal to m.length-1? Is there any charAt at position pointed by that value? — Pshemo
– Pshemo, Commented Jun 6, 2016 at 14:22

Seek Addo · Accepted Answer · 2016-06-06 14:25:14Z

1

try this: You look through with the n because it has the longest length. I hope this helps. String m="cd e"; String n="abcd efghi";

    for (int i = 0; i < n.length(); i++) {
        for (int j = 0; j <i; j++) {
            if (i <= m.length()){ // to prevent indexoutOfbound exception
                if(m.charAt(j)==n.charAt(i) ) {
                    System.out.println(m.charAt(j)+"-->"+i);
                }
            }
        }
    }

output:

c-->2
d-->3
 -->4

edited Jun 6, 2016 at 14:25

answered Jun 6, 2016 at 14:05

Seek Addo

1,9033 gold badges22 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

sujays · Accepted Answer · 2016-06-06 14:25:03Z

0

package default1;

public class Test {
public static void main(String[] args) {
    String m="cd e";
    String n="abcd efghi";

    System.out.println(n.indexOf(m));

}
}

answered Jun 6, 2016 at 14:25

sujays

1712 silver badges17 bronze badges

Comments

nitika · Accepted Answer · 2016-06-06 14:35:52Z

0

int i = 0;
    int j = 0;
    int index = 0;
    boolean previousMatch = false;
    while (i < n.length()) {
        if (j == m.length()) {
            break;
        }
        if (m.charAt(j) == n.charAt(i)) {
            if (!previousMatch) {
                previousMatch = true;
                index = i;
            }
            j++;
        } else {
            previousMatch = false;
            index = 0;
            j = 0;
        }
        i++;
    }
    if (previousMatch)
        System.out.println(index);

answered Jun 6, 2016 at 14:35

nitika

3033 silver badges12 bronze badges

Collectives™ on Stack Overflow

String Index - sub string and main string Something is not working properly

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related