如何使用正则表达式验证印度的Pin码

给定一个介于0到9之间的正数字符串，任务是使用正则表达式检查该数字是否为有效的密码。

The valid pin code of India must satisfy the following conditions.

1. It can be only six digits.
2. It should not start with zero.
3. First digit of the pin code must be from 1 to 9.
4. Next five digits of the pin code may range from 0 to 9.
5. It should allow only one white space, but after three digits, although this is optional.

例子：

Input: num = “132103”
Output: true
Explanation:
The given number satisfies all the above mentioned conditions.

Input: num = “201 305”
Output: true
Explanation:
The given number satisfies all the above mentioned conditions.

Input: num = “014205”
Output: false
Explanation:
The given number start with zero, therefore it is not a valid pin code of India.

Input: num = “1473598”
Output: false
Explanation:
The given number contains seven digits, therefore it is not a valid pin code of India.

方法：可以通过使用正则表达式来解决此问题。

1. 获取号码。
2. 创建一个正则表达式以验证印度的PIN码，如下所述：

   regex = "^[1-9]{1}[0-9]{2}\\s{0, 1}[0-9]{3}$";
   

   在哪里：

   • ^代表数字的开头。
   • [1-9] {1}表示PIN码中的起始数字，范围从1到9。
   • [0-9] {2}表示密码中的后两位数字，范围从0到9。
   • \\ s {0，1}表示引脚代码中的空白，该空白可以出现一次或永远不会发生。
   • [0-9] {3}表示密码中的后三位数字，范围为0到9。
   • $代表数字的结尾。
3. 在Java，使用regex匹配给定的数字，这可以通过使用Pattern.matcher()来完成。
4. 如果数字与给定的正则表达式匹配，则返回true，否则返回false。

下面是上述方法的实现。

Java

// Java program to validate the pin code
// of India using Regular Expression.
  
import java.util.regex.*;
  
class GFG {
  
    // Function to validate the pin code of India.
    public static boolean isValidPinCode(String pinCode)
    {
  
        // Regex to check valid pin code of India.
        String regex
            = "^[1-9]{1}[0-9]{2}\\s{0,1}[0-9]{3}$";
  
        // Compile the ReGex
        Pattern p = Pattern.compile(regex);
  
        // If the pin code is empty
        // return false
        if (pinCode == null) {
            return false;
        }
  
        // Pattern class contains matcher() method
        // to find matching between given pin code
        // and regular expression.
        Matcher m = p.matcher(pinCode);
  
        // Return if the pin code
        // matched the ReGex
        return m.matches();
    }
  
    // Driver Code.
    public static void main(String args[])
    {
  
        // Test Case 1:
        String num1 = "132103";
        System.out.println(
            num1 + ": "
            + isValidPinCode(num1));
  
        // Test Case 2:
        String num2 = "201 305";
        System.out.println(
            num2 + ": "
            + isValidPinCode(num2));
  
        // Test Case 3:
        String num3 = "014205";
        System.out.println(
            num3 + ": "
            + isValidPinCode(num3));
  
        // Test Case 4:
        String num4 = "1473598";
        System.out.println(
            num4 + ": "
            + isValidPinCode(num4));
    }
}

Python3

# Python3 program to validate the  
# pin code of India using Regular 
# Expression. 
import re
  
# Function to validate the pin code
# of India. 
def isValidPinCode(pinCode):
      
    # Regex to check valid pin code
    # of India.
    regex = "^[1-9]{1}[0-9]{2}\\s{0,1}[0-9]{3}$"; 
  
    # Compile the ReGex 
    p = re.compile(regex);
      
    # If the pin code is empty
    # return false
    if (pinCode == ''):
        return False;
          
    # Pattern class contains matcher() method
    # to find matching between given pin code
    # and regular expression.
    m = re.match(p, pinCode);
      
    # Return True if the pin code
    # matched the ReGex else False
    if m is None:
        return False
    else:
        return True
  
# Driver code 
if __name__ == "__main__":
      
    # Test case 1
    num1 = "132103";
    print(num1, ": ", isValidPinCode(num1));
      
    # Test case 2:
    num2 = "201 305";
    print(num2, ": ", isValidPinCode(num2));
      
    # Test case 3:
    num3 = "014205";
    print(num3, ": ", isValidPinCode(num3));
      
    # Test case 4:
    num4 = "1473598";
    print(num4, ": ", isValidPinCode(num4));
      
# This code is contributed by AnkitRai01

输出：

132103: true
201 305: true
014205: false
1473598: false