Given some US Currencies, the task is to check if they are valid or not using regular expressions. Rules for the valid Currency are:
- It should always start with “$“.
- It can contain only digits (0 – 9) and at most one dot.
- It should not contain any whitespaces and alphabets.
- Comma Separator (‘, ‘) should be there after every three digits interval.
Examples:
Input: “$0.84”
Output: TrueInput: “12345”
Output: False
Explanation: “$” is missing in the starting.
Approach: The problem can be solved based on the following idea:
Create a regex pattern to validate the number as written below:
regex = “^\$([0-9]{1, 3}(\, [0-9]{3})*|([0-9]+))(\.[0-9]{2})?$”OR
regex=”^\$(\d{1, 3}(\, \d{3})*|(\d+))(\.\d{2})?$“
Where,
- ^ : Represents, beginning of the string
- \$ : Should always start from $
- \d : Digits should be there
- \. : dot can be present or not
- \d{2} : Only digits are allowed after dot
Follow the below steps to implement the idea:
- Create a regex expression for US Currency.
- Use Pattern class to compile the regex formed.
- Use the matcher function to check whether the US Currency is valid or not.
- If it is valid, return true. Otherwise, return false.
Below is the implementation of the above approach.
// C++ program to validate the // US CURRENCY using Regular // Expression #include <bits/stdc++.h> #include <regex> using namespace std;
// Function to validate the // US CURRENCY string isValid_USCurrency(string str) { // Regex to check valid
// US CURRENCY.
const regex pattern(
"^\\$(\\d{1, 3}(\\, \\d{3})*|(\\d+))(\\.\\d{2})?$" );
// If the str
// is empty return false
if (str.empty()) {
return "false" ;
}
// Return true if the str
// matched the ReGex
if (regex_match(str, pattern)) {
return "true" ;
}
else {
return "false" ;
}
} // Driver Code int main()
{ // Test Case 1:
string str1 = "$123458" ;
cout << isValid_USCurrency(str1) << endl;
// Test Case 2:
string str2 = "$1, 234, 567.89" ;
cout << isValid_USCurrency(str2) << endl;
// Test Case 3:
string str3 = "$0.84" ;
cout << isValid_USCurrency(str3) << endl;
// Test Case 4:
string str4 = "$12, 3456.01" ;
cout << isValid_USCurrency(str4) << endl;
// Test Case 5:
string str5 = "$1.234" ;
cout << isValid_USCurrency(str5) << endl;
return 0;
} |
// Java program to validate the // US Currency using Regular Expression import java.util.regex.*;
class GFG {
// Function to validate the
// US Currency
public static boolean isValid_USCurrency(String str)
{
// Regex to check valid US Currency
String regex
= "^\\$(\\d{1, 3}(\\, \\d{3})*|(\\d+))(\\.\\d{2})?$" ;
// Compile the ReGex
Pattern p = Pattern.compile(regex);
// If the str is empty return false
if (str == null ) {
return false ;
}
// Pattern class contains matcher()
// method to find matching between
// given str using regex.
Matcher m = p.matcher(str);
// Return if the str
// matched the ReGex
return m.matches();
}
// Driver Code.
public static void main(String args[])
{
// Test Case 1:
String str1 = "$123458" ;
System.out.println(isValid_USCurrency(str1));
// Test Case 2:
String str2 = "$1, 234, 567.89" ;
System.out.println(isValid_USCurrency(str2));
// Test Case 3:
String str3 = "$0.84" ;
System.out.println(isValid_USCurrency(str3));
// Test Case 4:
String str4 = "$12, 3456.01" ;
System.out.println(isValid_USCurrency(str4));
// Test Case 5:
String str5 = "$1.234" ;
System.out.println(isValid_USCurrency(str5));
}
} |
# Python3 program to validate # US Currency using Regular Expression import re
# Function to validate # US Currency def isValid_USCurrency( str ):
# Regex to check valid US Currency
regex = "^\\$(\\d{1, 3}(\\, \\d{3})*|(\\d+))(\\.\\d{2})?$"
# Compile the ReGex
p = re. compile (regex)
# If the string is empty
# return false
if ( str = = None ):
return "false"
# Return if the string
# matched the ReGex
if (re.search(p, str )):
return "true"
else :
return "false"
# Driver code if __name__ = = '__main__' :
# Test Case 1:
str1 = "$123458"
print (isValid_USCurrency(str1))
# Test Case 2:
str2 = "$1, 234, 567.89"
print (isValid_USCurrency(str2))
# Test Case 3:
str3 = "$0.84"
print (isValid_USCurrency(str3))
# Test Case 4:
str4 = "$12, 3456.01"
print (isValid_USCurrency(str4))
# Test Case 5:
str5 = "$1.234"
print (isValid_USCurrency(str5))
|
// C# program to validate the // US Currency using Regular Expression using System;
using System.Text.RegularExpressions;
public class GFG {
// Function to validate the
// US Currency
public static bool isValid_USCurrency( string str)
{
// Regex to check valid US Currency
string regex
= "^\\$(\\d{1, 3}(\\, \\d{3})*|(\\d+))(\\.\\d{2})?$" ;
// Compile the ReGex
Regex p = new Regex(regex);
// If the str is empty return false
if (str == null ) {
return false ;
}
// Pattern class contains matcher()
// method to find matching between
// given str using regex.
Match m = p.Match(str);
// Return if the str
// matched the ReGex
return m.Success;
}
// Driver Code.
public static void Main()
{
// Test Case 1:
string str1 = "$123458" ;
Console.WriteLine(isValid_USCurrency(str1));
// Test Case 2:
string str2 = "$1, 234, 567.89" ;
Console.WriteLine(isValid_USCurrency(str2));
// Test Case 3:
string str3 = "$0.84" ;
Console.WriteLine(isValid_USCurrency(str3));
// Test Case 4:
string str4 = "$12, 3456.01" ;
Console.WriteLine(isValid_USCurrency(str4));
// Test Case 5:
string str5 = "$1.234" ;
Console.WriteLine(isValid_USCurrency(str5));
}
} // This code is contributed by Pushpesh Raj. |
// Javascript program to validate // US Currency using Regular Expression // Function to validate the // US Currency function isValid_USCurrency(str) {
// Regex to check valid
// US Currency
let regex = new RegExp(/^\$(\d{1, 3}(\, \d{3})*|(\d+))(\.\d{2})?$/);
// if str
// is empty return false
if (str == null ) {
return "false" ;
}
// Return true if the str
// matched the ReGex
if (regex.test(str) == true ) {
return "true" ;
}
else {
return "false" ;
}
} // Driver Code // Test Case 1: let str1 = "$123458" ;
console.log(isValid_USCurrency(str1)); // Test Case 2: let str2 = "$1, 234, 567.89" ;
console.log(isValid_USCurrency(str2)); // Test Case 3: let str3 = "$0.84" ;
console.log(isValid_USCurrency(str3)); // Test Case 4: let str4 = "$12, 3456.01" ;
console.log(isValid_USCurrency(str4)); // Test Case 5: let str5 = "$1.234" ;
console.log(isValid_USCurrency(str5)); |
true true true false false
Time Complexity: O(N) for each test case, where N is the length of the given string.
Auxiliary Space: O(1)
Related Articles: