Regular expression to find bar

Question

I need to validate a field and it must have the following format: two letters/numbers. Ex.: RN/1234567. The two letters will always be uppercase and the number quantity has no limit.

Answer 1

I’m not very good at Regex, but I think this one’s for you:

[A-Z]{2}[\/][0-9]{1,}

Explanation:

• [A-Z]{2}:Find two characters from A to Z
• [\/]: Find a bar
• [1-9]{1,}: Finds from 1 to infinity numbers

Answer 2

In general, if you want to validate if there are two letters, uppercase, followed by a bar and then only numbers, no specific size you can use:

[A-Z]{2}\/[0-9]{1,}

This will make it valid for doos characters between A and Z. Then a slider, escaped, to require the slider to exist after both letters. Then check for numbers, between 0 and 9, at least there must be a number to infinity.

Answer 3

A solution: str.match(/\w{2}\/\d+/g)

• \w{2} any letter (wOrd) 2 times
• \/ a bar /
• \d+ any digit (digit) 1 or more times

Answer 4

To complement the above answers, to use the regular expression explained above you can do as follows:

PHP

$codigo = 'RN/1234567';

$regex = '~[A-Z]{2}\/[1-9]{1,}~';

if (preg_match($regex, $codigo)) {
    echo 'Código válido!';
}  else {
     echo 'Insira um código válido!';
}

Javascript

var codigo = 'RN/1234560';
var regex = /[A-Z]{2}\/[1-9]{1,}/g;
if (regex.test(codigo)) {
    console.log('Código válido!');
} else {
    console.log('Insira um código válido!');
}

Answer 5

With Javascript, you can do so:

function validarMeuCampo(texto) {
    var captura = texto.match(/[A-Z][A-Z]\/[0-9]+/);
    var valido = !!captura && captura.length == 1 && captura[0].length == texto.length;
    return valido;
}

Explanation:

The regular expression /[A-Z][A-Z]\/[0-9]+/ captures two uppercase letters, followed by a bar, followed by a number of numbers. The number amount is unlimited, but there must be at least one number (that’s what the + to the right of the numbers makes).

The method match of the String type takes a regular expression and returns an array of portions of the String to which the expression found something. If you find nothing, returns null.

The operator ! does a negation. It happens that in Javascript all is deniable. Denying twice is a way of finding out whether a variable that should be an object has value, because the negation of an object is false, and the negation of null is true. In other words: the opposite of my opposite is a boolean value that tells me whether I have value or not.

Putting it all together now: find in the given text snippets that match the regular expression. If you find a single result that matches the string, then the string is valid for your rule.