Flash cards
Review the key moves
What is the main idea behind Java Scanner hasNextLong() Method?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
Which statement best captures the main point of this lesson?
Complete the missing token from the example code.
// ___ a scanner object Scanner myObj = new Scanner("A long is a number between -9,223,372,036,854,775,808 and 9,223,372,036,854,775,807");Put the learning moves in the order that makes the concept easiest to apply.
❮ Scanner Methods
Example
Print the value of every long integer in the string:
// Create a scanner object Scanner myObj = new Scanner("A long is a number between -9,223,372,036,854,775,808 and 9,223,372,036,854,775,807");
// Print the value of every long in the scanner
while (myObj.hasNext()) {
if (myObj.hasNextLong()) {
System.out.println(myObj.nextLong());
} else {
myObj.next();
}
}Definition and Usage
The hasNextLong() method returns true if the next token represents a number that can be stored by the long data type, which is any whole number between -9,223,372,036,854,775,808 and 9,223,372,036,854,775,807.
The scanner is able to interpret digit groupings, such as using a comma for separating groups of 3 digits. The format of the groupings depends on the locale settings of the scanner, which can be changed with the useLocale() method.
If the radix parameter is used, then it interprets numbers using the radix. For example, a radix of 16 would interpret numbers as hexadecimal (digits 0 to 9 and A to F). If the radix parameter is not used then it interprets numbers using the scanner's radix, which is 10 by default but it can be changed with the useRadix() method.
What is a token?
A token is a sequence of characters separated from other tokens by delimiters. The default delimiter is a block of whitespace characters but it can be changed with the useDelimiter() method.
One of the following
public boolean hasNextLong()public boolean hasNextLong(int
radix )Parameter Values
| Parameter | Description |
|---|---|
| radix | Optional. Specifies the radix used to interpret numbers. The radix specifies how many different symbols can be used to represent a digit in a number. |
Technical Details
| Returns: | A boolean value which is true if the next token represents a long value. |
|---|---|
| Throws: | IllegalStateException - If the scanner has been closed. |
❮ Scanner Methods