How to split a string into hex?

[samuelxin]

how to translate String to Hex by byte?

[Weedpacket]

With the [man]ord[/man] and [man]dechex[/man] functions (and an operator or two, and chuck in a flow control instruction in the process, but you get the idea).

[samuelxin]

but can you teach me how?
i have VB code as below, can you parse it and trans to php code?
tks

  datalen = HexT(str1, data(), 0)

Function HexT(ip_str As String, op_str() As Byte, op_start As Integer) As Integer
    'translate String to Hex by byte.
    'can setting output start position; ret=byte array tail
    Dim Start As Integer, Cnt As Integer
    Dim tmpstr As String
    Dim data As Integer

Start = 1
Cnt = 0 + op_start
Do
    tmpstr = Mid$(ip_str, Start, 1)

    Start = Start + 1
    If tmpstr = "" Then Exit Do
    If tmpstr = "\" Then
        tmpstr = "&H" & Mid$(ip_str, Start, 2)
        Start = Start + 2
        op_str(Cnt) = Val(tmpstr)
        Cnt = Cnt + 1
    Else
        data = Asc(tmpstr)
        op_str(Cnt) = data Mod 256
        Cnt = Cnt + 1
        If data >= 256 Then
            op_str(Cnt) = data / 256
            Cnt = Cnt + 1
        End If
    End If
Loop
HexIpB = Cnt

End Function