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The java.lang.String.contains() method returns true if and only if this string contains the specified sequence of char values.ExampleLive Demopublic class Sample { public static void main(String args[]){ String str = "Hello how are you welcome to tutorialspoint"; String test = "tutorialspoint"; Boolean bool = str.contains(test); System.out.println(bool); } }Outputtrue
The toString() method of the String class returns itself a string.ExampleLive 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.toString()); } }OutputReturn Value :Welcome to Tutorialspoint.comThe value of method variants of the String class accepts different variables such as integer, float, boolean etc.. and converts them into String.ExampleLive Demopublic class Sample { public static void main(String args[]){ int i = 200; float f = 12.0f; ... Read More
Java String class provides several variants of valueOf() method. These accept various data types and convert them into String.ExampleLive Demopublic class Sample { public static void main(String args[]){ int i = 200; float f = 12.0f; char c = 's'; char[] ch = {'h', 'e', 'l', 'l', 'o'}; String data = String.valueOf(i); System.out.println(String.valueOf(i)); System.out.println(String.valueOf(f)); System.out.println(String.valueOf(c)); System.out.println(String.valueOf(ch)); } }Output200 12.0 s hello
Java lang package provides a Double class which has methods to convert Double to String and vice versa. You can convert a String to a double using the parseDouble() method and double to String using the toString() methodExampleLive Demopublic class StringDouble { public static void main(String args[]){ Double data1 = 2.2; String str = Double.toString(data1); System.out.println(str); Double data2 = Double.parseDouble(str); System.out.println(data2); } }Output2.2 2.2
Java lang package provides Integer class which has methods to convert an 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.ExampleLive 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
You can change the cases using the toUpperCase() and toLowerCase() methods of the String class.ExampleLive Demopublic class Sample { public static void main(String args[]){ String str = "Hello how are you"; String strUpper = str.toUpperCase(); System.out.println("Lower to upper : "+strUpper); String strLower = str.toLowerCase(); System.out.println("Upper to lower : "+strLower); } }OutputLower to upper : HELLO HOW ARE YOU Upper to lower : hello how are you
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.ExampleLive 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
The split(String regex) method of the String class splits this string around matches of the given regular expression.ExampleLive Demopublic class Sample{ public static void main(String args[]){ String s = "|A|BB||CCC|||"; String[] words = s.split("\|"); for (String string : words) { System.out.println(string); } } }OutputA BB CCC
The compareTo() method compares the Number object that invoked the method to the argument. It is possible to compare Byte, Long, Integer, etc.However, two different types cannot be compared, both the argument and the Number object invoking the method should be of the same type.ExampleLive Demopublic class Test { public static void main(String args[]) { Integer x = 5; System.out.println(x.compareTo(3)); System.out.println(x.compareTo(5)); System.out.println(x.compareTo(8)); } }Output1 0 -1
This method has two variants. The first variant converts all of the characters in this String to upper case using the rules of the given Locale. This is equivalent to calling toUpperCase(Locale.getDefault()).The second variant takes a locale as an argument to be used while converting into upper case.ExampleLive 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.toUpperCase()); } }OutputReturn Value :WELCOME TO TUTORIALSPOINT.COM