Java Code to Node Js or PHP Function

Convert code from java to php or node js equivalent function runnable Java function public static byte[] hexStringToBytes(String hexString) { if (hexString == null || [login to view URL]("")) { return null; } hexString = [login to view URL](); char[] hexCharacter = [login to view URL](); for (int i = 0; i < [login to view URL]; i++) { if (-1 == charToByte(hexCharacter[i])) { return null; } } int length = [login to view URL]() / 2; char[] hexChars = [login to view URL](); byte[] d = new byte[length]; for (int i = 0; i < length; i++) { int pos = i * 2; d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1])); } return d; } public static byte charToByte(char c) { return (byte) "0123456789ABCDEF".indexOf(c); } public static String bytesToHexString(byte[] src){ StringBuilder stringBuilder = new StringBuilder(""); if (src == null || [login to view URL] <= 0) { return null; } for (int i = 0; i < [login to view URL]; i++) { int v = src[i] & 0xFF; String hv = [login to view URL](v); if ([login to view URL]() < 2) { [login to view URL](0); } [login to view URL](hv); } return [login to view URL](); } public static float signedBytes2Float(byte byHeight, byte byLow) { float nTempPointLeft = byHeight; int nTempPointRight = (byLow & 0xFF); float fTempPointRight = ((float)nTempPointRight) / 256; float result; if (nTempPointLeft < 0) { result = nTempPointLeft - fTempPointRight; } else { result = nTempPointLeft + fTempPointRight; } BigDecimal bigTemp = new BigDecimal(result); return [login to view URL](2, BigDecimal.ROUND_HALF_UP).floatValue(); }