从字符串中删除大写、小写、特殊、数字和非数字字符

给定长度为N 的字符串str ，任务是从此字符串删除大写、小写、特殊、数字和非数字字符，并在同时修改后打印该字符串。

例子：

Input: str = “GFGgfg123$%”

Output: After removing uppercase characters: gfg123$%

             After removing lowercase characters: GFG123$%

            After removing special characters: GFGgfg123

           After removing numeric characters: GFGgfg$%

           After removing non-numeric characters: 123

Input: str = “J@va12”

Output: After removing uppercase characters: @va12

             After removing lowercase characters: J@12

            After removing special characters: Jva12

           After removing numeric characters: J@va           

          After removing non-numeric characters: 12

朴素的方法：最简单的方法是遍历字符串并删除大写、小写、特殊、数字和非数字字符。以下是步骤：

1.遍历由字符字符串字符从开始到结束。

2. 检查每个字符的 ASCII 值是否符合以下条件：

• 如果 ASCII 值在[65, 90]范围内，则它是大写字符。因此，跳过这些字符并将其余字符添加到另一个字符串并打印出来。
• 如果 ASCII 值在[97, 122]范围内，则它是小写字符。因此，跳过这些字符并将其余字符添加到另一个字符串并打印出来。
• 如果 ASCII 值在[32, 47] 、 [58, 64] 、 [91, 96]或[123, 126] 的范围内，则它是特殊字符。因此，跳过这些字符并将其余字符添加到另一个字符串并打印出来。
• 如果 ASCII 值在[48, 57]范围内，则它是一个数字字符。因此，跳过这些字符并将其余字符添加到另一个字符串并打印出来。
• 否则字符是非数字字符。因此，跳过这些字符并将其余字符添加到另一个字符串并打印出来。

时间复杂度： O(N)
辅助空间： O(1)

正则表达式方法：这个想法是使用正则表达式来解决这个问题。以下是步骤：

1. 创建正则表达式以从字符串中删除大写、小写、特殊、数字和非数字字符，如下所述：

• regexToRemoveUpperCaseCharacters  = “[A-Z]”
• regexToRemoveLowerCaseCharacters = “[a-z]”
• regexToRemoveSpecialCharacters = “[^A-Za-z0-9]”
• regexToRemoveNumericCharacters = “[0-9]”
• regexToRemoveNon-NumericCharacters = “[^0-9]”

2. 使用 Pattern.compile() 方法编译给定的正则表达式以创建模式。

3. 使用 Pattern.matcher() 将给定的字符串与上述所有正则表达式匹配。

4. 使用 Matcher.replaceAll() 方法用目标字符串替换每个匹配的模式。

下面是上述方法的实现：

C++

// C++ program to remove uppercase, lowercase
// special, numeric, and non-numeric characters
#include 
#include 
using namespace std;
 
// Function to remove uppercase characters
string removingUpperCaseCharacters(string str)
{
  // Create a regular expression
  const regex pattern("[A-Z]");
 
  // Replace every matched pattern with the
  // target string using regex_replace() method
  return regex_replace(str, pattern, "");
}
 
// Function to remove lowercase characters
string removingLowerCaseCharacters(string str)
{
  // Create a regular expression
  const regex pattern("[a-z]");
 
  // Replace every matched pattern with the
  // target string using regex_replace() method
  return regex_replace(str, pattern, "");
}
 
// Function to remove special characters
string removingSpecialCharacters(string str)
{
  // Create a regular expression
  const regex pattern("[^A-Za-z0-9]");
 
  // Replace every matched pattern with the
  // target string using regex_replace() method
  return regex_replace(str, pattern, "");
}
 
// Function to remove numeric characters
string removingNumericCharacters(string str)
{
  // Create a regular expression
  const regex pattern("[0-9]");
 
  // Replace every matched pattern with the
  // target string using regex_replace() method
  return regex_replace(str, pattern, "");
}
 
// Function to remove non-numeric characters
string removingNonNumericCharacters(string str)
{
  // Create a regular expression
  const regex pattern("[^0-9]");
 
  // Replace every matched pattern with the
  // target string using regex_replace() method
  return regex_replace(str, pattern, "");
}
 
int main()
{
  // Given String str
  string str = "GFGgfg123$%";
 
  // Print the strings after the simultaneous
  // modifications
  cout << "After removing uppercase characters: "
       << removingUpperCaseCharacters(str) << endl;
  cout << "After removing lowercase characters: "
       << removingLowerCaseCharacters(str) << endl;
  cout << "After removing special characters: "
       << removingSpecialCharacters(str) << endl;
  cout << "After removing numeric characters: "
       << removingNumericCharacters(str) << endl;
  cout << "After removing non-numeric characters: "
       << removingNonNumericCharacters(str) << endl;
 
  return 0;
}
 
// This article is contributed by yuvraj_chandra

Java

// Java program to remove uppercase, lowercase
// special, numeric, and non-numeric characters
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class GFG
{
 
    // Function to remove uppercase characters
    public static String
    removingUpperCaseCharacters(String str)
    {
 
        // Create a regular expression
        String regex = "[A-Z]";
 
        // Compile the regex to create pattern
        // using compile() method
        Pattern pattern = Pattern.compile(regex);
 
        // Get a matcher object from pattern
        Matcher matcher = pattern.matcher(str);
 
        // Replace every matched pattern with the
        // target string using replaceAll() method
        return matcher.replaceAll("");
    }
 
    // Function to remove lowercase characters
    public static String
    removingLowerCaseCharacters(String str)
    {
 
        // Create a regular expression
        String regex = "[a-z]";
 
        // Compile the regex to create pattern
        // using compile() method
        Pattern pattern = Pattern.compile(regex);
 
        // Get a matcher object from pattern
        Matcher matcher = pattern.matcher(str);
 
        // Replace every matched pattern with the
        // target string using replaceAll() method
        return matcher.replaceAll("");
    }
 
    // Function to remove special characters
    public static String
    removingSpecialCharacters(String str)
    {
 
        // Create a regular expression
        String regex = "[^A-Za-z0-9]";
 
        // Compile the regex to create pattern
        // using compile() method
        Pattern pattern = Pattern.compile(regex);
 
        // Get a matcher object from pattern
        Matcher matcher = pattern.matcher(str);
 
        // Replace every matched pattern with the
        // target string using replaceAll() method
        return matcher.replaceAll("");
    }
 
    // Function to remove numeric characters
    public static String
    removingNumericCharacters(String str)
    {
 
        // Create a regular expression
        String regex = "[0-9]";
 
        // Compile the regex to create pattern
        // using compile() method
        Pattern pattern = Pattern.compile(regex);
 
        // Get a matcher object from pattern
        Matcher matcher = pattern.matcher(str);
 
        // Replace every matched pattern with the
        // target string using replaceAll() method
        return matcher.replaceAll("");
    }
 
    // Function to remove non-numeric characters
    public static String
    removingNonNumericCharacters(String str)
    {
 
        // Create a regular expression
        String regex = "[^0-9]";
 
        // Compile the regex to create pattern
        // using compile() method
        Pattern pattern = Pattern.compile(regex);
 
        // Get a matcher object from pattern
        Matcher matcher = pattern.matcher(str);
 
        // Replace every matched pattern with the
        // target string using replaceAll() method
        return matcher.replaceAll("");
    }
 
    // Driver Code
    public static void main(String[] args)
    {
        // Given String str
        String str = "GFGgfg123$%";
 
        // Print the strings after the simultaneous
        // modifications
        System.out.println(
            "After removing uppercase characters: "
            + removingUpperCaseCharacters(str));
        System.out.println(
            "After removing lowercase characters: "
            + removingLowerCaseCharacters(str));
        System.out.println(
            "After removing special characters: "
            + removingSpecialCharacters(str));
        System.out.println(
            "After removing numeric characters: "
            + removingNumericCharacters(str));
        System.out.println(
            "After removing non-numeric characters: "
            + removingNonNumericCharacters(str));
    }
}

Python3

# Python3 program to remove
# uppercase, lowercase special,
# numeric, and non-numeric characters
import re
 
# Function to remove
# uppercase characters
def removingUpperCaseCharacters(str):
 
    # Create a regular expression
    regex = "[A-Z]"
 
    # Replace every matched pattern 
    # with the target string using
    # sub() method
    return (re.sub(regex, "", str))
 
# Function to remove lowercase
# characters
def removingLowerCaseCharacters(str):
 
    # Create a regular expression
    regex = "[a-z]"
 
    # Replace every matched
    # pattern with the target
    # string using sub() method
    return (re.sub(regex, "", str))
 
def removingSpecialCharacters(str):
 
    # Create a regular expression
    regex = "[^A-Za-z0-9]"
 
    # Replace every matched pattern
    # with the target string using
    # sub() method
    return (re.sub(regex, "", str))
 
def removingNumericCharacters(str):
 
    # Create a regular expression
    regex = "[0-9]"
 
    # Replace every matched
    # pattern with the target
    # string using sub() method
    return (re.sub(regex, "", str))
 
def  removingNonNumericCharacters(str):
 
    # Create a regular expression
    regex = "[^0-9]"
 
    # Replace every matched pattern
    # with the target string using
    # sub() method
    return (re.sub(regex, "", str))
 
str = "GFGgfg123$%"
print("After removing uppercase characters:",
       removingUpperCaseCharacters(str))
print("After removing lowercase characters:",
       removingLowerCaseCharacters(str))
print("After removing special characters:",
       removingSpecialCharacters(str))
print("After removing numeric characters:",
       removingNumericCharacters(str))
print("After removing non-numeric characters:",
       removingNonNumericCharacters(str))
 
# This code is contributed by avanitrachhadiya2155

输出

After removing uppercase characters: gfg123$%
After removing lowercase characters: GFG123$%
After removing special characters: GFGgfg123
After removing numeric characters: GFGgfg$%
After removing non-numeric characters: 123

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