Found 9326 Articles for Object Oriented Programming

The toCharArray() method of a String class converts this string to a character array.ExampleLive Demoimport java.lang.*; public class StringDemo {    public static void main(String[] args) {       // converts String value to character array type value       String str = " Java was developed by James Gosling";       char retval[] = str.toCharArray();       // displays the converted value       System.out.println("Converted value to character array = ");       System.out.println(retval);    } }OutputConverted value to character array = Java was developed by James Gosling

The StringTokenizer class of the java. util package allows an application to break a string into tokens.This class is a legacy class that is retained for compatibility reasons although its use is discouraged in new code.Its methods do not distinguish among identifiers, numbers, and quoted strings.These class methods do not even recognize and skip comments.ExampleLive Demoimport java.util.*; public class Sample {    public static void main(String[] args) {       // creating string tokenizer       StringTokenizer st = new StringTokenizer("Come to learn");       // checking next token       System.out.println("Next token is : " + st.nextToken());    } }OutputNext token is : Come

Following are the important constructors of the StringTokenizer class.Sr.No.Constructor & Description1StringTokenizer(String str)This constructor a string tokenizer for the specified string.2StringTokenizer(String str, String delim)This constructor constructs string tokenizer for the specified string.3StringTokenizer(String str, String delim, boolean returnDelims)This constructor constructs a string tokenizer for the specified string.

To swap the contents of two strings (say s1 and s2) without the third, first of all concatenate them and store in s1. Now using the substring() method of the String class store the value of s1 in s2 and vice versa.Example Live Demopublic class Sample {    public static void main(String args[]){       String s1 = "tutorials";       String s2 = "point";       System.out.println("Value of s1 before swapping :"+s1);       System.out.println("Value of s2 before swapping :"+s2);       int i = s1.length();       s1 = s1+s2;       s2 = ... Read More

The StringTokenizer class of the java.util package allows an application to break a string into tokens.This class is a legacy class that is retained for compatibility reasons although its use is discouraged in new code.Its methods do not distinguish among identifiers, numbers, and quoted strings.This class methods do not even recognize and skip comments.ExampleLive Demoimport java.util.*;   public class Sample {    public static void main(String[] args) {         // creating string tokenizer       StringTokenizer st = new StringTokenizer("Come to learn");         // checking next token       System.out.println("Next token is : " + st.nextToken());   }     }OutputNext token is : Come

The StringBuffer and StringBuilder classes are used when there is a necessity to make a lot of modifications to Strings of characters.Unlike Strings, objects of type StringBuffer and String builder can be modified over and over again without leaving behind a lot of new unused objects.The StringBuilder class was introduced as of Java 5 and the main difference between the StringBuffer and StringBuilder is that StringBuilder’s methods are not thread safe (not synchronized).It is recommended to use StringBuilder whenever possible because it is faster than StringBuffer. However, if the thread safety is necessary, the best option is StringBuffer objects. Read More

Java lang package provides Integer class which has methods to convert integer to String and vice versa. You can convert a String to an integer using the parseInt() method and Integer to String using the toString() method.Example Live Demopublic class Sample {    public static void main(String args[]) {       String str = "1212";       int num = Integer.parseInt(str);       System.out.println(num);       String st = Integer.toString(num);       System.out.println();    } }Output1212 1212

Convert the given string into an array of characters for each character of the array verify whether it is upper case, lower case, digit or, any other character using isUpperCase(), isLowerCase(), isDigit() method of the Character class.ExampleLive Demopublic class Sample2 {    public static void main(String args[]) {       String data = "Hello HOW are you MR 51";       char [] charArray = data.toCharArray();       int upper = 0;       int lower = 0;       int digit = 0;       int others = 0;       int totalChars = data.length();       for(int i=0; i

Following are the various constructors provided by the StringBuilder class.S.N.Constructor & Description1StringBuilder()This constructs a string builder with no characters in it and an initial capacity of 16 characters.2StringBuilder(CharSequence seq)This constructs a string builder that contains the same characters as the specified CharSequence.3StringBuilder(int capacity)This constructs a string builder with no characters in it and an initial capacity specified by the capacity argument.4StringBuilder(String str)This constructs a string builder initialized to the contents of the specified string.

The isEmpty() method of the String class returns true if the length of the current string 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