Flash cards
Review the key moves
What is the main idea behind Java Scanner hasNextDouble() 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("The probability is 45.6 percent");Put the learning moves in the order that makes the concept easiest to apply.
❮ Scanner Methods
Example
Print the value of every floating point number in the string:
// Create a scanner object Scanner myObj = new Scanner("The probability is 45.6 percent");
// Print the value of every floating point number in the scanner
while (myObj.hasNext()) {
if (myObj.hasNextDouble()) {
System.out.println(myObj.nextDouble());
} else {
myObj.next();
}
}Definition and Usage
The hasNextDouble() method returns true if the next token represents a valid number.
The scanner is able to interpret digit groupings, such as using a comma for separating groups of 3 digits. The format of the groupings and the character used as a decimal point depend on the locale settings of the scanner, which can be changed with the useLocale() 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.
Syntax
public boolean hasNextDouble()Technical Details
| Returns: | A boolean value which is true if the next token represents a valid number. |
|---|---|
| Throws: | IllegalStateException - If the scanner has been closed. |
❮ Scanner Methods