I have a function in JavaScript which is expecting a byte array to be passed into it from Native C++ code. For example:

function OnEvent(event, data1)
{
     console.log("data1[0] = " + data1[0]);
}

I would like for it to print 0x55 or even the decimal value of it. For some reason, I am seeing the following in the console log:

How can I print the hex value of the byte or even the decimal value without printing the character?

UPDATE

I went to the link below thanks to Vinothbabu. I used the unpack function:

function unpack(str) { 
    var bytes = []; 
    $("#homePage").append("str.length = " + str.length + "<br>"); 

    for(var i = 0, n = str.length; i < n; i++) { 
        var char = str.charCodeAt(i); 
        $("#homePage").append("char is equal to " + char + "<br>"); 
        bytes.push(char >>> 8, char & 0xFF); 
    }

    return bytes; 
}

It prints "char is equal to 65533" and the value of "bytes" prints out "255, 253" which means it has a value of 0xFFFD.

This is not the data/payload that I was expecting. Do you know why there are 2 bytes?

I have a function in JavaScript which is expecting a byte array to be passed into it from Native C++ code. For example:

function OnEvent(event, data1)
{
     console.log("data1[0] = " + data1[0]);
}

I would like for it to print 0x55 or even the decimal value of it. For some reason, I am seeing the following in the console log:

How can I print the hex value of the byte or even the decimal value without printing the character?

UPDATE

I went to the link below thanks to Vinothbabu. I used the unpack function:

function unpack(str) { 
    var bytes = []; 
    $("#homePage").append("str.length = " + str.length + "<br>"); 

    for(var i = 0, n = str.length; i < n; i++) { 
        var char = str.charCodeAt(i); 
        $("#homePage").append("char is equal to " + char + "<br>"); 
        bytes.push(char >>> 8, char & 0xFF); 
    }

    return bytes; 
}

It prints "char is equal to 65533" and the value of "bytes" prints out "255, 253" which means it has a value of 0xFFFD.

This is not the data/payload that I was expecting. Do you know why there are 2 bytes?

• javascript
• c++
• char
• byte

• Try data1[0].toString(16) – bfavaretto Commented Sep 28, 2013 at 1:38
• 1 codereview.stackexchange./questions/3569/… – Thalaivar Commented Sep 28, 2013 at 1:42
• Thanks Vinothbabu. I followed your link related to packing/unpacking. However, using unpack(): code function unpack(str) { var bytes = []; $("#homePage").append("str.length = " + str.length + "<br>"); for(var i = 0, n = str.length; i < n; i++) { var char = str.charCodeAt(i); $("#homePage").append("char is equal to " + char + "<br>"); bytes.push(char >>> 8, char & 0xFF); } return bytes; }code It prints "char is equal to 65533" and the bytes prints out 255, 253, which means it has a value of 0xFFFD – code Commented Oct 1, 2013 at 19:53

1 Answer 1

I believe this will do the trick:

console.log("data1[0] = " + data1[0].toString(16));