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法律研究Java菜单驱动程序检查数字类型
在Java中，我们有用于表示数字的原始数值数据类型，例如short、byte、int、long、float和double。这些数值数据类型允许我们根据其范围表示不同的整数和实数，因为特定数据类型具有其下限和上限。
以下是6种原始数值数据类型
byte: Range -128 to 127 (Size 1 byte) short: Range -32,768 to 32,767 (Size 2 bytes) int: Range -2,147,483,648 to 2,147,483,647 (Size 4 bytes) long: Range -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 (8 bytes) float: Range 6 to 7 decimal digits for Fractional Numbers (Size 4 bytes) double: Range 15 decimal digits for Fractional Numbers (Size 8 bytes)
在本文中，我们将学习如何使用Java编程语言检查数字的类型。我们将使用switch case实现该应用程序。
举一些例子：
示例1
Suppose we have taken an integer type of value i.e. 222222 then it must show “number entered is a valid integer”.
示例2
Suppose we have taken a double type of value i.e 120.0 then it must show “number entered is a valid double”.
示例3
Suppose we have taken a float type of value i.e 2.1 then it must show “number entered is a valid float”.
示例4
Suppose we have taken a byte type of value i.e 23 then it must show “number entered is a valid byte”.
示例5
Suppose we have taken a short type of value i.e 32,765 then it must show “number entered is a valid short”.
示例6
Suppose we have taken a long type of value i.e 222222222222 then it must show “number entered is a valid long”.
语法
要检查数字的类型，我们将检查其数据类型。如果数据类型匹配，则结果为正，否则为负。要检查它，我们有一个名为hasNextData_Type的函数。
以下是检查“整数数据类型”的语法：
hasNextInt()
以下是检查“双精度数据类型”的语法：
hasNextDouble()
以下是检查“浮点数据类型”的语法：
hasNextFloat()
以下是检查“字节数据类型”的语法：
hasNextByte()
以下是检查“短整型数据类型”的语法：
hasNextShort()
以下是检查“长整型数据类型”的语法：
hasNextLong()
算法
步骤1 - 提示用户输入选择。
步骤2 - 显示菜单。
步骤3 - 提示用户输入数据。
步骤4 - 使用switch case跳转到选择并执行操作。
步骤5 - 打印结果。
让我们来看一下程序以便更好地理解。
示例
import java.util.*; public class Main{ public static void main(String args[]){ mainLoop: while (true) { Scanner sc = new Scanner( System.in ); System.out.println("\n***Menu***"); System.out.println("1. Check for Integer"); System.out.println("2. Check for Double"); System.out.println("3. Check for Float"); System.out.println("4. Check for Byte"); System.out.println("5. Check for Short"); System.out.println("6. Check for Long"); System.out.println("7. Terminate the program"); System.out.println("Enter action number (1-7): "); int command = sc.nextInt(); switch(command) { case 1: int input = 0; System.out.println("Enter an integer for its validation"); if(sc.hasNextInt()) { input = sc.nextInt(); System.out.println(input+" is a valid Integer"); } else{ System.out.println("It is not a valid Integer"); } break; case 2: double input1 = 0; System.out.println("Enter a Double for its validation"); if(sc.hasNextDouble()) { input1 = sc.nextDouble(); System.out.println(input1+" is a valid Double"); } else { System.out.println("It is not a valid Double"); } break; case 3: float input2; System.out.println("Enter a Float for its validation"); if(sc.hasNextFloat()) { input2 = sc.nextFloat(); System.out.println(input2+" is a valid Float"); } else{ System.out.println("It is not a valid Float"); } break; case 4: byte input3 = 0; System.out.println("Enter a Byte for its validation"); if(sc.hasNextByte()) { input3 = sc.nextByte(); System.out.println(input3+" is a valid Byte"); } else{ System.out.println("It is not a valid Byte"); } break; case 5: short input4 = 0; System.out.println("Enter a Short for its validation"); if(sc.hasNextShort()) { input4 = sc.nextShort(); System.out.println(input4+" is a valid Short"); } else{ System.out.println("It is not a valid Short"); } break; case 6: long input5 = 0; System.out.println("Enter a Short for its validation"); if(sc.hasNextLong()) { input5 = sc.nextLong(); System.out.println(input5+" is a valid Long"); } else{ System.out.println("It is not a valid Long"); } break; case 7: System.out.println("Program terminated"); break mainLoop; default: System.out.println("Wrong choice!!"); } } } }
输出
***Menu*** 1. Check for Integer 2. Check for Double 3. Check for Float 4. Check for Byte 5. Check for Short 6. Check for Long 7. Terminate the program Enter action number (1-7): 1 Enter an integer for its validation 22222 22222 is a valid Integer ***Menu*** 1. Check for Integer 2. Check for Double 3. Check for Float 4. Check for Byte 5. Check for Short 6. Check for Long 7. Terminate the program Enter action number (1-7): 2 Enter a Double for its validation 2.4 2.4 is a valid Double ***Menu*** 1. Check for Integer 2. Check for Double 3. Check for Float 4. Check for Byte 5. Check for Short 6. Check for Long 7. Terminate the program Enter action number (1-7): 3 Enter a Float for its validation 2.5 2.5 is a valid Float ***Menu*** 1. Check for Integer 2. Check for Double 3. Check for Float 4. Check for Byte 5. Check for Short 6. Check for Long 7. Terminate the program Enter action number (1-7): 4 Enter a Byte for its validation 123 123 is a valid Byte ***Menu*** 1. Check for Integer 2. Check for Double 3. Check for Float 4. Check for Byte 5. Check for Short 6. Check for Long 7. Terminate the program Enter action number (1-7): 5 Enter a Short for its validation 1234 1234 is a valid Short ***Menu*** 1. Check for Integer 2. Check for Double 3. Check for Float 4. Check for Byte 5. Check for Short 6. Check for Long 7. Terminate the program Enter action number (1-7): 6 Enter a Short for its validation 345 345 is a valid Long ***Menu*** 1. Check for Integer 2. Check for Double 3. Check for Float 4. Check for Byte 5. Check for Short 6. Check for Long 7. Terminate the program Enter action number (1-7): 7 Program terminated
在本文中，我们探讨了如何使用菜单驱动方法在Java中检查数字的类型。
更新于：2022年12月27日
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