Convert Object Array to String Array in Java

Sai Nath
Updated on 30-Jul-2019 22:30:21

5K+ Views

As list.toArray() returns an Object[], it can be converted to String array by passing the String[] as parameter. See the example below.import java.util.ArrayList; import java.util.List; public class Tester { public static void main(String[] args) { List data = new ArrayList(); data.add("A"); data.add("B"); data.add("C"); //Object[] objects = data.toArray(); String[] strObjects = data.toArray(new String[0]); for(String obj: strObjects) { System.out.println(obj); } } }OutputA B C

Remove FOREIGN KEY Constraint from MySQL Table

George John
Updated on 30-Jul-2019 22:30:21

11K+ Views

We can remove FOREIGN KEY constraint from a column of an existing table by using DROP keyword along with ALTER TABLE statement. Syntax ALTER TABLE table_name DROP FOREIGN KEY constraint_name Here constraint name is the name of foreign key constraint which we applied while creating the table. If no constraint name is specified then MySQL will provide constraint name which can be checked by SHOW CREATE TABLE statement. Example The following query will delete the FOREIGN KEY constraint from ‘orders’ table − mysql> Alter table orders DROP FOREIGN KEY orders_ibfk_1; Query OK, 0 rows affected (0.22 sec) ... Read More

What is Java Method Area

Ayyan
Updated on 30-Jul-2019 22:30:21

2K+ Views

JVM has a method area common across all the threads. It contains per-class elements like constant pool, fields, method local data, method code, constructor codes etc. which are used in class and initialization of objects/interfaces.This method area gets created during JVM start-up. It is generally part of Heap area. It could be of fixed size or vary. Its memory may not be contiguous. JVM implementation can give control to programmer over Method area creation, its sizing etc. If method area memory is not sufficient to satisfy an allocation request then JVM throws OutOfMemoryError.

Difference Between Size and Capacity of a Vector in Java

Sravani S
Updated on 30-Jul-2019 22:30:21

2K+ Views

The size of a vector represents the number of components in the vector. The capacity of a vector represents the maximum number of elements the vector can hold.Example:import java.util.*; public class VectorDemo {    public static void main(String args[]) {       Vector v = new Vector(3, 2);       System.out.println("Initial size: " + v.size());       System.out.println("Initial capacity: " + v.capacity());       v.addElement(new Integer(1));       v.addElement(new Integer(2));       v.addElement(new Integer(3));       v.addElement(new Integer(4));       System.out.println("Capacity after four additions: " + v.capacity());       v.addElement(new ... Read More

Replace String with Another in Java

Anjana
Updated on 30-Jul-2019 22:30:21

424 Views

The replace() method of the returns a new string resulting from replacing all occurrences of oldChar in this string with newChar.Example Live Demoimport java.io.*; public class Test {    public static void main(String args[]) {       String Str = new String("Welcome to Tutorialspoint.com");       System.out.print("Return Value :" );       System.out.println(Str.replace('o', 'T'));       System.out.print("Return Value :" );       System.out.println(Str.replace('l', 'D'));    } }OutputReturn Value :WelcTme tT TutTrialspTint.cTm Return Value :WeDcome to TutoriaDspoint.com

Can a Vector Contain Heterogeneous Objects in Java

Ramu Prasad
Updated on 30-Jul-2019 22:30:21

1K+ Views

Since a vector stores elements in the form of objects, you can store objects of various types (heterogeneous) in it.Example:import java.util.*; class Demo{} public class VectorSample {    public static void main(String args[]) {       Demo obj = new Demo();       Vector v = new Vector(3, 2);       System.out.println("Initial size: " + v.size());       System.out.println("Initial capacity: " + v.capacity());       v.addElement(new Integer(1));       v.addElement(new String("krishna"));       v.addElement(new Float(3.5f));       v.addElement(obj);       System.out.println("Capacity after four additions: " + v.capacity());    } }

Check for Null, Empty, or White Space Only String in Java

Anjana
Updated on 30-Jul-2019 22:30:21

2K+ Views

We can verify whether the given string is empty using the isEmpty() method of the String class. This method returns true only if length() is 0.Example Live Demoimport java.lang.*; public class StringDemo {    public static void main(String[] args) {       String str = "tutorialspoint";       // prints length of string       System.out.println("length of string = " + str.length());       // checks if the string is empty or not       System.out.println("is this string empty? = " + str.isEmpty());    } }Outputlength of string = 14 is this string empty? = false

Getting Data in Front-End Tools from SAP HANA Database

Anil SAP Gupta
Updated on 30-Jul-2019 22:30:21

398 Views

In SAP HANA database, you have different system schema. _SYS_BIC schema in SAP HANA database is used to store column views of all the activated objects in HANA repository.  When an object is created and activated (HANA Modeling views, Stored Procedures), run time objects are saved under _SYS_BIC/Column views in database.These column views are used by front-end tools like BusinessObjects to get the data in a query.

Use goto Statement in JavaScript

Abhinanda Shri
Updated on 30-Jul-2019 22:30:21

3K+ Views

JavaScript goto statement is a reserved keyword. Generally, according to web standards it isn’t considered a good practice to use goto statement.Using goto with JavaScript preprocessing is still considered good as shown below.var a = 0; [lbl] beginning: console.log("Demo Text!"); a++; if(i < 424) goto beginning;The above code gets translated like the following −var a = 0; beginning: while(true) { console.log("Demo Text!"); a++; if(i < 424) continue beginning; break; }

Convert Java String to Int

Alankritha Ammu
Updated on 30-Jul-2019 22:30:21

359 Views

The parseXxx() method is used to get the primitive data type of a certain String. In this case to convert a String to integer you could use the parseInt() method.Example Live Demopublic class Test {    public static void main(String args[]) {       int x =Integer.parseInt("9");       double c = Double.parseDouble("5");       int b = Integer.parseInt("444",16);       System.out.println(x);       System.out.println(c);       System.out.println(b);    } }Output9 5.0 1092

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