java scanner

掃描器類的nextLong()方法 (Scanner Class nextLong() method)

Syntax:

句法：

    public long nextLong();
public long nextLong(int rad);

• nextLong() method is available in java.util package.

  nextLong()方法在java.util包中可用。

• nextLong() method is used to read the next token of the input as a long value at the implicit radix of this Scanner.

  nextLong()方法用于讀取輸入的下一個令牌，作為此Scanner的隱含基數處的長值。

• nextLong(int rad) method is used to read the next token of the input as a long value at the explicit or given radix(rad) of this Scanner.

  nextLong(int rad)方法用于在此Scanner的顯式或給定基數(rad)處讀取輸入的下一個標記作為長值。

• These methods may throw an exception at the time of representing an input as a long value.

  在將輸入表示為長值時，這些方法可能會引發異常。

  • InputMismatchException: This exception may throw when the next token of the input mismatch.InputMismatchException ：當輸入的下一個標記不匹配時，可能引發此異常。
  • NoSuchElementException: This exception may throw when no such element exists.NoSuchElementException ：如果不存在這樣的元素，則可能引發此異常。
  • IllegalStateException: This exception may throw when this Scanner is not opened.IllegalStateException ：如果未打開此掃描器，則可能引發此異常。

• These are non-static methods and it is accessible with the class object only and if we try to access these methods with the class name then we will get an error.

  這些是非靜態方法，只能通過類對象訪問，如果嘗試使用類名稱訪問這些方法，則會收到錯誤消息。

Parameter(s):

參數：

• In the first case, nextLong(),

  在第一種情況下， nextLong() ，

  • It does not accept any parameter.

• In the second case, nextLong(int rad),

  在第二種情況下， nextLong(int rad) ，

  • int rad – represents the radix used to manipulate the token as a long value.
  • int rad –表示用于操縱令牌的基數為長值。

Return value:

返回值：

In both the cases, the return type of the method is long, it retrieves the long value read from the input.

在這兩種情況下，方法的返回類型都是long ，它檢索從輸入讀取的long值。

Example 1:

范例1：

// Java program to demonstrate the example 
// of nextLong() method of Scanner
import java.util.*;
import java.util.regex.*;
public class NextLong {
public static void main(String[] args) {
String str = "Java Programming! 3 * 8= 24 + b";
long l = 101245l;
// Instantiates Scanner
Scanner sc = new Scanner(str);
while (sc.hasNext()) {
// By using nextLong() method isto
// return the next token as a 
// long at the implicit radix
if (sc.hasNextLong()) {
long next_l = sc.nextLong();
System.out.println("sc.nextLong()): " + next_l);
}
System.out.println(sc.next());
}
// Scanner closed
sc.close();
}
}

Output

輸出量

Java
Programming!
sc.nextLong()): 3
*
8=
sc.nextLong()): 24
+
b

Example 2:

范例2：

import java.util.*;
import java.util.regex.*;
public class NextLong {
public static void main(String[] args) {
String str = "Java Programming! 3 * 8= 24 + b";
long l = 101245l;
// Instantiates Scanner
Scanner sc = new Scanner(str);
while (sc.hasNext()) {
// By using nextLong(9) method isto
// return the next token as a 
// long at the explicit radix
if (sc.hasNextLong()) {
long next_l = sc.nextLong(9);
System.out.println("sc.nextLong(9)): " + next_l);
}
System.out.println(sc.next());
}
// Scanner closed
sc.close();
}
}

Output

輸出量

Java
Programming!
sc.nextLong(9)): 3
*
8=
sc.nextLong(9)): 22
+
b

翻譯自: https://www.includehelp.com/java/scanner-nextlong-method-with-example.aspx

java scanner