PHP: Parse raw input as a float, with best guess for the decimal character (dot or comma). Useful if you do not know original locale or when you are processing user input.

floatval-locale-guess.php

<?php

function parseFloatGuess($rawValue) {
    if (!$rawValue) {
        return 0;
    }

    $lastCommaPosition = strrpos($rawValue, ',');
    $lastDotPosition = strrpos($rawValue, '.');

    // Special case: Neither present
    if ($lastDotPosition === false && $lastCommaPosition === false) {
        return floatval($rawValue);
    }

    // Special case: Comma is at index zero (e.g. ",123" same as ".123" or "0.123")
    if ($lastCommaPosition === 0 && $lastDotPosition === false) {
        $rawValue = str_replace(',', '.', $rawValue);
        return floatval($rawValue);
    }

    // Guess what decimal separator we are using, based on which char we see last

    // For example, a string formatted as "123,456.00" has a dot last, so we'll guess US dot
    // Another example, a string formatted as "123.456,00" has a comma last, so we'll guess EU comma
    // But a string like "123,456" is rather ambiguous and we're also forced to guess EU comma dec

    $decimalChar = ($lastCommaPosition > $lastDotPosition ? ',' : '.');
    $thousandsChar = ($decimalChar === '.' ? ',' : '.');

    // Special guess: If there's more than one type of a char, it's probably our thousands sep
    // e.g. we should probably interpret "1,456,789" as "," being the thousands separator
    if (substr_count($rawValue, ',') > 1) {
        $decimalChar = '.';
        $thousandsChar = ',';
    } else if (substr_count($rawValue, '.') > 1) {
        $decimalChar = ',';
        $thousandsChar = '.';
    }

    // Either way, dispose of what we think is our thousands char, and change to dot decimal char
    $rawValue = str_replace($thousandsChar, '', $rawValue);
    $rawValue = str_replace($decimalChar, '.', $rawValue);

    return floatval($rawValue);
}

var_dump(parseFloatGuess("0")); // int(0)
var_dump(parseFloatGuess("0.123")); // double(0.123)
var_dump(parseFloatGuess("0,123")); // double(0.123)
var_dump(parseFloatGuess("1,100.12")); // double(1100.12)
var_dump(parseFloatGuess("1.100.444,12")); // double(1100444.12)
var_dump(parseFloatGuess("1,100,555")); // double(1100555)
var_dump(parseFloatGuess(".123")); // double(0.123)
var_dump(parseFloatGuess(",456")); // double(0.456)

Thanks!
Great idea for solving the problem when you cannot control what decimal char you are going to get.