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Articles by karthikeya Boyini
Page 99 of 143
Create a simple calculator using Java Swing
Swing API is a set of extensible GUI Components to ease the developer's life to create JAVA based Front End/GUI Applications. It is built on top of AWT API and acts as a replacement of AWT API since it has almost every control corresponding to AWT controls.Following example showcases a simple calculator application.import java.awt.BorderLayout; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextField; public class Calculator implements ActionListener { private static JTextField inputBox; Calculator(){} public static void main(String[] args) { createWindow(); } ...
Read MoreHow can we check the indexes created by a UNIQUE constraint on a MySQL table?
SHOW INDEX statement is used to check the indexes created by a UNIQUE constraint on a MySQL table.SyntaxSHOW INDEX from table_name;ExampleSuppose we have the table ‘empl’ which have a UNIQUE constraint on column ‘empno’.mysql> describe empl; +--------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+-------------+------+-----+---------+-------+ | empno | int(11) | YES | UNI | NULL | | | F_name | varchar(20) | YES | | NULL | | +--------+-------------+------+-----+---------+-------+ 2 rows in set (0.23 sec)Now as we know that ...
Read MoreWhat happens when we apply NOT NULL constraint, with ALTER TABLE statement, to a column contains NULL values?
In this case, MySQL will return an error message regarding data truncated for the column. Following is an example of demonstrating it −ExampleSuppose we have a table ‘test2’ which contains a NULL value in column ‘ID’ at 2nd row. Now, if we will try to declare the column ID to NOT NULL then MySQL will return the error as follows −mysql> Select * from test2; +------+--------+ | ID | Name | +------+--------+ | 1 | Gaurav | | NULL | Rahul | +------+--------+ 2 rows in set (0.00 sec) mysql> ALTER TABLE TEST2 MODIFY ID INT NOT NULL; ERROR 1265 (01000): Data truncated for column 'ID' at row 2
Read MoreHow to add binary numbers using Python?
If you have binary numbers as strings, you can convert them to ints first using int(str, base) by providing the base as 2. Then add the numbers like you'd normally do. Finally convert it back to a string using the bin function. For example,a = '001' b = '011' sm = int(a,2) + int(b,2) c = bin(sm) print(c)This will give the output:0b100
Read MoreWhere to put comments in an if...elif..else construct?
You can put comments anywhere in an if...elif...else statement, ie before each of these blocks or within each of these blocks. Note that you cannot put multiline comments before elif and else blocks though, as these comments are actually strings which imply a break in the whole construct. For example,# If check if True: # Another Comment style print("If block") # Else if statement elif False: # Another Comment style print("elif block") # Else else: # Another Comment style print("Else block")This will give the output:If block
Read MoreHow to sort a nested Python dictionary?
If you have a dictionary of the following format:{ 'KEY1':{'name':'foo', 'data':1351, 'completed':100}, 'KEY2':{'name':'bar', 'data':1541, 'completed':12}, 'KEY3':{'name':'baz', 'data':58413, 'completed':18} }And you want to sort by the key, completed within each entry, in a ascending order, you can use the sorted function with a lambda that specifies which key to use to sort the data. For example, my_collection = { 'KEY1':{'name':'foo', 'data':1351, 'completed':100}, 'KEY2':{'name':'bar', 'data':1541, 'completed':12}, 'KEY3':{'name':'baz', 'data':58413, 'completed':18} } sorted_keys = sorted(my_collection, key=lambda x: (my_collection[x]['completed'])) print(sorted_keys)This will give the output:['KEY2', 'KEY3', 'KEY1']
Read MoreSimpson's 1/3 Rule for definite integral
Like the Trapezoidal Rule, Simpson’s 1/3rd rule is also used to find the integral value from the range a to b. The main difference between trapezoidal and the Simpson’s 1/3rd rule is, in the trapezoidal rule, the whole sections are divided into some trapezoids, but in this case, each trapezoid are also divided into two parts.For this rule, we will follow this formula:Here h is the width of the interval, and n is the number of intervals. We can find the h by using Input and OutputInput: The function f(x): (x+(1/x). The lower and upper limit: 1, 2. The number of ...
Read MoreLucky Numbers
Lucky numbers are some special integer numbers. From basic numbers, some special numbers are eliminated by their position. Instead of their value, for their position, the numbers are eliminated. The numbers which are not deleted, they are the lucky numbers.The number deletion follows some rule. At first, every second number are deleted, after that, all 3rd numbers are deleted and so on.Here is some example −1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 (1 – 25 all) 1 3 5 7 9 11 ...
Read MoreWord Wrap Problem
A sequence of words is given, there is a limit on the number of characters for each line. By putting line breaks, in such a way that lines are printed clearly.The lines must be balanced, when some lines have lots of extra spaces and some lines are containing a small number of extra spaces, it will balance them to separate lines. It tries to use the same number of extra spaces to make them balanced.This algorithm will produce how many words can be placed in one line, and how many lines are needed.Input and OutputInput: The length of words for ...
Read MoreMinimum Number of Jumps Problem
In this problem, a list of positive integers is given. Each integer is denoting that how many maximum steps that can be made from the current element. Starting from the first element, we have to find the minimum number of jumps to reach the end item of the list.For the dynamic programming approach, a jumps array is defined to store the minimum number of jumps required. Like for a value of jumps[i], it indicates that how many minimum jumps are needed to reach the ith index of the array from the 0th index.Input and OutputInput: A list of integers. {1, ...
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