The nextFloat() method of java.util.Scanner class scans the next token of the input as a Float(). If the translation is successful, the scanner advances past the input that matched.
Syntax:
Java
Java
Java
Java
public float nextFloat()Parameters: The function does not accepts any parameter. Return Value: This function returns the Float scanned from the input. Exceptions: The function throws three exceptions as described below:
- InputMismatchException: if the next token does not matches the Float regular expression, or is out of range
- NoSuchElementException: if input is exhausted
- IllegalStateException: if this scanner is closed
// Java program to illustrate the
// nextFloat() method of Scanner class in Java
// without parameter
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
String s = "Gfg 9 + 6 = 12.0";
// create a new scanner
// with the specified String Object
Scanner scanner = new Scanner(s);
while (scanner.hasNext()) {
// if the next is a Float,
// print found and the Float
if (scanner.hasNextFloat()) {
System.out.println("Found Float value :"
+ scanner.nextFloat());
}
// if no float is found,
// print "Not Found:" and the token
else {
System.out.println("Not found Float() value :"
+ scanner.next());
}
}
scanner.close();
}
}
Output:
Program 2: To demonstrate InputMismatchException
Not found Float() value :Gfg Found Float value :9.0 Not found Float() value :+ Found Float value :6.0 Not found Float() value := Found Float value :12.0
// Java program to illustrate the
// nextFloat() method of Scanner class in Java
// InputMismatchException
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
try {
String s = "Gfg 9 + 6 = 12.0";
// create a new scanner
// with the specified String Object
Scanner scanner = new Scanner(s);
while (scanner.hasNext()) {
// if the next is a Float
// print found and the Float
// since the value 60 is out of range
// it throws an exception
System.out.println("Next Float value :"
+ scanner.nextFloat());
}
scanner.close();
}
catch (Exception e) {
System.out.println("Exception thrown: " + e);
}
}
}
Output:
Program 3: To demonstrate NoSuchElementException
Exception thrown: java.util.InputMismatchException
// Java program to illustrate the
// nextFloat() method of Scanner class in Java
// NoSuchElementException
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
try {
String s = "Gfg";
// create a new scanner
// with the specified String Object
Scanner scanner = new Scanner(s);
// Trying to get the next Float value
// more times than the scanner
// Hence it will throw exception
for (int i = 0; i < 5; i++) {
// if the next is a Float,
// print found and the Float
if (scanner.hasNextFloat()) {
System.out.println("Found Float value :"
+ scanner.nextFloat());
}
// if no Float is found,
// print "Not Found:" and the token
else {
System.out.println("Not found Float value :"
+ scanner.next());
}
}
scanner.close();
}
catch (Exception e) {
System.out.println("Exception thrown: " + e);
}
}
}
Output:
Program 4: To demonstrate IllegalStateException
Not found Float value :Gfg Exception thrown: java.util.NoSuchElementException
// Java program to illustrate the
// nextFloat() method of Scanner class in Java
// IllegalStateException
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
try {
String s = "Gfg 9 + 6 = 12.0";
// create a new scanner
// with the specified String Object
Scanner scanner = new Scanner(s);
// close the scanner
scanner.close();
System.out.println("Scanner Closed");
System.out.println("Trying to get "
+ "next Float value");
while (scanner.hasNext()) {
// if the next is a Float,
// print found and the Float
if (scanner.hasNextFloat()) {
System.out.println("Found Float value :"
+ scanner.nextFloat());
}
// if no Float is found,
// print "Not Found:" and the token
else {
System.out.println("Not found Float value :"
+ scanner.next());
}
}
}
catch (Exception e) {
System.out.println("Exception thrown: " + e);
}
}
}
Output:
Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#nextFloat()Scanner Closed Trying to get next Float value Exception thrown: java.lang.IllegalStateException: Scanner closed