Java - search for substring in array

Question

I am trying to find a subString inside a string, in an arraylist, but I can't get it working. It has to loop through the arraylist until it finds the sub string, and then stop.

Here is what I have so far

    private static void teamSearch(String teamName) {

    String subString = teamName;
    String string = "";
    boolean contains = false;

    while (contains = false){
    for (int i = 0; i < clubList.size(); i++){
        string = clubList.get(i).aliases;
        contains = string.contains(subString);
    }
    System.out.println(contains);
    }
}

Any help in getting this working would be much appreciated :) Thank you!

Don't use while, break the for loop when constains is true. — Bhesh Gurung
– Bhesh Gurung, Commented May 30, 2013 at 7:03

stinepike · Accepted Answer · 2013-05-30 07:08:33Z

1

use

while (contains == false)

instead

while (contains = false)

= is an assign operator and == is comparision operator. you are assigning false to contains in while loop. You have to compare the values

edited May 30, 2013 at 7:08

answered May 30, 2013 at 7:02

stinepike

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Comments

michaelb958--GoFundMonica · Accepted Answer · 2013-05-30 07:28:32Z

1

Avoid while loop. Use break statement. If not careful, while loops can cause infinite loops.

private static void teamSearch(String teamName) {
    String subString = teamName;
    String string = "";
    boolean contains = false;

    for (int i = 0; i < clubList.size(); i++){
        string = clubList.get(i).aliases;
        if (string.contains(subString)) {
           contains = true; 
           break;
        }
    }
    System.out.println(contains);
}

edited May 30, 2013 at 7:28

michaelb958--GoFundMonica

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answered May 30, 2013 at 7:07

Kechit Goyal

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Comments

Dinuk · Accepted Answer · 2013-05-30 07:13:42Z

0

Your inner for loop keeps on rolling - even if it finds the the alias with the substring.

You need to terminate the loop when it finds a match. This is a naive, yet correct implementation

private static void teamSearch(String teamName) {

    String subString = teamName;
    String string = "";
    boolean contains = false;

    for (int i = 0; i < clubList.size(); i++){
        string = clubList.get(i).aliases;
        if (string.contains(subString){ 
          contains = true;
          break;
        } 
    }
    System.out.println(contains);
}

answered May 30, 2013 at 7:13

Dinuk

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Comments

Alankar Srivastava · Accepted Answer · 2013-05-30 07:02:57Z

0

Your while loop condition is wrong change it to while ( contains == false )

answered May 30, 2013 at 7:02

Alankar Srivastava

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Comments

Suresh Atta · Accepted Answer · 2013-05-30 07:03:59Z

0

you are trying to assign a value there.you need to check the value equal or not

while (contains == false) //checking equality


while (contains = false) //assigning

answered May 30, 2013 at 7:03

Suresh Atta

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Comments

MadProgrammer · Accepted Answer · 2013-05-30 07:07:52Z

0

You could use

while (!contains) {...}

But it might be easier to simply drop the while loop and break the for loop

for (int i = 0; i < clubList.size(); i++){
    string = clubList.get(i).aliases;
    contains = string.contains(subString);
    if (contains) {
        break;
    }
}

answered May 30, 2013 at 7:07

MadProgrammer

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Comments

Mostafa Jamareh · Accepted Answer · 2013-05-30 07:17:53Z

0

it could be useful

boolean flag = false;

    String subString = "nice";


    ArrayList<String> arrayList = new ArrayList<String>(2);


    arrayList.add("good morning");


    arrayList.add("that is nice");


    for (String element : arrayList) {


        if (element.contains(subString))


            flag = true;


        else


            flag = false;


    }

answered May 30, 2013 at 7:17

Mostafa Jamareh

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