const regex = /\b(34[0-9]{2}[ -])([0-9]{6}[ -])[0-9]{5}\b|\b34[0-9]{13}\b|\b(37[0-9]{2}[ -])([0-9]{6}[ -])[0-9]{5}\b|\b37[0-9]{13}\b/gm;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('\\b(34[0-9]{2}[ -])([0-9]{6}[ -])[0-9]{5}\\b|\\b34[0-9]{13}\\b|\\b(37[0-9]{2}[ -])([0-9]{6}[ -])[0-9]{5}\\b|\\b37[0-9]{13}\\b', 'gm')
const str = `American Express
Requirements: American Express cards start with the number 34 or 37 and have 15 digits. Pattern is 4-6-5 when having spaces or dashes.
Pattern Parts:
Starts with number 34 and 15 length:
1) \\b(34[0-9]{2}[ -])([0-9]{6}[ -])[0-9]{5}\\b|\\b34[0-9]{13}\\b
Starts with number 37 and 15 length:
2) \\b(37[0-9]{2}[ -])([0-9]{6}[ -])[0-9]{5}\\b|\\b37[0-9]{13}\\b
Combining 1-2 to form one pattern:
\\b(34[0-9]{2}[ -])([0-9]{6}[ -])[0-9]{5}\\b|\\b34[0-9]{13}\\b|\\b(37[0-9]{2}[ -])([0-9]{6}[ -])[0-9]{5}\\b|\\b37[0-9]{13}\\b
Test Cases:
Positive (Should fire):
15 length, no space, start with 34 Here is the cc: 342312341234123 Thanks.
15 length, dashes, start with 34 3423-123456-12345
15 length, spaces, start with 34 3423 123456 12345
15 length, no space, start with 37 372112341234123
15 length, dashes, start with 37 3721-123456-12345
15 length, spaces, start with 37 3721 123456 12345
Embedded in sentence with space:
15 length, no space, start with 34 Here is the cc: 342312341234112
15 length, dashes, start with 34 Here is the cc: 3423-123456-12345
15 length, spaces, start with 34 Here is the cc: 3423 123456 12345
15 length, no space, start with 37 Here is the cc: 372112341234123
15 length, dashes, start with 37 Here is the cc: 3721-123456-12345
15 length, spaces, start with 37 Here is the cc: 3721 123456 12345
15 length, no space, start with 34 Credit Card#:342312341234112
15 length, dashes, start with 34 Credit Card#:3423-123456-12345
15 length, spaces, start with 34 Credit Card#:3423 123456 12345
15 length, no space, start with 37 Credit Card#:372112341234123
15 length, dashes, start with 37 Credit Card#:3721-123456-12345
15 length, spaces, start with 37 Credit Card#:3721 123456 12345
Negative (Should Not Fire):
15 length, no space, not start with 34 352312341234112
15 length, dashes, not start with 34 3523-123456-12345
15 length, spaces, not start with 34 3523 123456 12345
15 length, no space, not start with 37 362112341234123
15 length, dashes, not start with 37 3621-123456-12345
15 length, spaces, not start with 37 3621 123456 12345
15 length, no space, start with 34, embedded Credit Card Number342312341234112
15 length, dashes, start with 34, malformed 3423-1234-1234-112
15 length num matching pattern but embedded User ID: 000000342312341234112000000`;
// Reset `lastIndex` if this regex is defined globally
// regex.lastIndex = 0;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions