w3resource

Java String Exercises: Check whether a substring appears before a period(.) within a given string

Java String: Exercise-73 with Solution

Write a Java program to check whether a substring appears before a period(.) within a given string.

Sample Solution:

Java Code:

import java.util.*;
public class Main
{
public Boolean abcBeforePeriod(String stng) 
{
  int len = stng.length();
  String abc = "abc";
  Boolean match = false;
  if (len < 3)
    return false;
  for (int i = 0; i < len - 2; i ++) 
  {
    String temp = stng.substring(i, i+3);
    if (temp.compareTo(abc) == 0 && i == 0)
      match = true;
    else if(temp.compareTo(abc) == 0 && stng.charAt(i-1) != 46)
      match = true;
  } 
  return match;
}
public static void main (String[] args)
    {
      Main m= new Main();
      String str1 =  "testabc.test";
      System.out.println("The given string is: "+str1);
      System.out.println("Is 'abc' appear before period? "+m.abcBeforePeriod(str1));
	  }
}

Sample Output:

The given strings is: testabc.test
Is 'abc' appear before period? true

The given string is: test.abctest
Is 'abc' appear before period? false

Pictorial Presentation:

Java String Exercises: Check whether a substring appears before a period(.) within a given string.

Flowchart:

Flowchart: Java String Exercises - Check whether a substring appears before a period(.) within a given string.

Java Code Editor:

Improve this sample solution and post your code through Disqus

Previous: Write a Java program to return true if a given string contain the string 'pop', but the middle 'o' also may other character.
Next: Write a Java program to check whether a prefix string creates using the first specific characters in a given string, appears somewhere else in the string.

What is the difficulty level of this exercise?



Java: Tips of the Day

Array vs ArrayLists:

The main difference between these two is that an Array is of fixed size so once you have created an Array you cannot change it but the ArrayList is not of fixed size. You can create instances of ArrayLists without specifying its size. So if you create such instances of an ArrayList without specifying its size Java will create an instance of an ArrayList of default size.

Once an ArrayList is full it re-sizes itself. In fact, an ArrayList is internally supported by an array. So when an ArrayList is resized it will slow down its performance a bit as the contents of the old Array must be copied to a new Array.

At the same time, it's compulsory to specify the size of an Array directly or indirectly while creating it. And also Arrays can store both primitives and objects while ArrayLists only can store objects.

Ref: https://bit.ly/3o8L2KH