How to remove the last characters from a string array?

Question

I have a String ArrayList filled with dates + time. The format is: "11 04 2017 - 12:45:54"

I would like to change the format so it only shows the date: "11 04 2017" and save it to another array.

How can i cut the last few characters of an array?

package com.example.hodor.stringcut;

    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.widget.EditText;

    import java.util.ArrayList;


public class MainActivity extends AppCompatActivity {

private EditText textView, textView1;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    textView = (EditText) findViewById(R.id.editText);
    textView1 = (EditText) findViewById(R.id.editText1);

    ArrayList<String> listDate = new ArrayList<>();
    ArrayList<String> listDate1 = new ArrayList<>();

    listDate.add("10 - 07 - 2017 - 12:32:45");
    listDate.add("10 - 07 - 2017 - 12:35:45");
    listDate.add("10 - 07 - 2017 - 12:36:45");
    listDate.add("10 - 07 - 2017 - 12:38:45");
    listDate.add("10 - 07 - 2017 - 12:30:45");

    textView.setText(listDate[1]);

    for (int i = 0; i < listDate.length; i++) {

        listDate1[i] = listDate[i].substring(0, listDate[i].length(), -10);
        textView.setText(listDate1[1]);
    }
}


}

Anybody can help me please?

thanks for the fast reply. cannot resolve method substring / length. im using java. — Roxby, Mar 07 '18 at 17:57
could i maybe only miss a import or does substring and length wont work on array? — Roxby, Mar 07 '18 at 18:02
Can you post a bit more of the code? What is the type of "listDate"? How is it instantiated? — Staros, Mar 07 '18 at 18:02
do i need to import a method in order to use length and substring? — Roxby, Mar 07 '18 at 18:09
Please modify your question to include the portion of the code that includes that list initialization. — Staros, Mar 07 '18 at 18:35
Assuming these Strings are strictly formatted in this manner you could look at `String.substring` and combine that with a loop that iterates over collections. — , Mar 07 '18 at 19:16
https://stackoverflow.com/questions/999172/how-to-parse-a-date — Brandon Kearby, Mar 07 '18 at 19:42

NIKHIL NEDIYODATH · Answer 1 · 2018-03-08T04:30:14.260

Try this. It works for me

package com.example.hodor.stringcut;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.EditText;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
    private EditText textView, textView1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textView = (EditText) findViewById(R.id.editText);
        textView1 = (EditText) findViewById(R.id.editText1);

        ArrayList<String> listDate = new ArrayList<>();
        ArrayList<String> listDate1 = new ArrayList<>();

        listDate.add("10 - 07 - 2017 - 12:32:45");
        listDate.add("10 - 07 - 2017 - 12:35:45");
        listDate.add("10 - 07 - 2017 - 12:36:45");
        listDate.add("10 - 07 - 2017 - 12:38:45");
        listDate.add("10 - 07 - 2017 - 12:30:45");

        textView.setText(listDate.get(1));

        for (int i = 0; i < listDate.size(); i++) {
            String date = listDate.get(i);
            listDate1.add(date.substring(0, date.length() -11));

        }
        textView.setText(listDate1.get(1));
    }
}

score 0 · Accepted Answer · answered Mar 07 '18 at 19:56

Your initial substring(0, length - 11) concept was correct. You're simply having a problem with types.

listDate is of type ArrayList. The substring method isn't applicable for it. It's applicable for its elements which are String types.

You're also mixing up the ArrayList type with java primitive arrays. Here's some example of how to utilize an ArrayList.

But once you comfortable with that, this code...

public static void main(String[] args) {
    String date = "10 - 07 - 2017 - 12:30:45";
    String modifiedDate = date.substring(0, date.length() - 10);
    System.out.println(modifiedDate);
}

Gives an output of...

10 - 07 - 2017

At a higher level, if what you're trying to do is parse dates then the link Brandon shared will be much more apt.

How to remove the last characters from a string array?

2 Answers2