I've never done this before and am not sure why it's outputting the infamous � encoding character. Any ideas on how to output characters as they should (ASCII+Unicode)? I think \u0041-\u005A should print A-Z in UTF-8, which Firefox is reporting is the page encoding.
var c = new Array("F","E","D","C","B","A",9,8,7,6,5,4,3,2,1,0);
var n = 0;
var d = "";
var o = "";
for (var i=16;i--;){
for (var j=16;j--;){
for (var k=16;k--;){
for (var l=16;l--;){
d = c[i].toString()
+ c[j].toString()
+ c[k].toString()
+ c[l].toString();
o += ( ++n + ": "
+ d + " = "
+ String.fromCharCode("\\u" + d)
+ "\n<br />" );
if(n>=500){i=j=k=l=0;} // stop early
}
}
}
}
document.write(o);
The .fromCharCode() function takes a number, not a string. You can't put together a string like that and expect the parser to do what you think it'll do; that's just not the way the language works.
You could ammend your code to make a string (without the '\u') from your hex number, and call
var n = parseInt(hexString, 16);
to get the value. Then you could call .fromCharCode() with that value.
A useful snippet for replacing all unicode-encoded special characters in a text is:
var rawText = unicodeEncodedText.replace(
/\\u([0-9a-f]{4})/g,
function (whole, group1) {
return String.fromCharCode(parseInt(group1, 16));
}
);
Using replace, fromCharCode and parseInt
If you want to use the \unnnn syntax to create characters, you have to do that in a literal string in the code. If you want to do it dynamically, you have to do it in a literal string that is evaluated at runtime:
var hex = "0123456789ABCDEF";
var s = "";
for (var i = 65; i <= 90; i++) {
var hi = i >> 4;
var lo = i % 16;
var code = "'\\u00" + hex[hi] + hex[lo] + "'";
var char = eval(code);
s += char;
}
document.write(s);
Of course, just using String.fromCharCode(i) would be a lot easier...
Related
How to convert from Hex string to ASCII string in JavaScript?
Ex:
32343630 it will be 2460
function hex2a(hexx) {
var hex = hexx.toString();//force conversion
var str = '';
for (var i = 0; i < hex.length; i += 2)
str += String.fromCharCode(parseInt(hex.substr(i, 2), 16));
return str;
}
hex2a('32343630'); // returns '2460'
Another way to do it (if you use Node.js):
var input = '32343630';
const output = Buffer.from(input, 'hex');
log(input + " -> " + output); // Result: 32343630 -> 2460
For completeness sake the reverse function:
function a2hex(str) {
var arr = [];
for (var i = 0, l = str.length; i < l; i ++) {
var hex = Number(str.charCodeAt(i)).toString(16);
arr.push(hex);
}
return arr.join('');
}
a2hex('2460'); //returns 32343630
You can use this..
var asciiVal = "32343630".match(/.{1,2}/g).map(function(v){
return String.fromCharCode(parseInt(v, 16));
}).join('');
document.write(asciiVal);
** for Hexa to String**
let input = '32343630';
Note : let output = new Buffer(input, 'hex'); // this is deprecated
let buf = Buffer.from(input, "hex");
let data = buf.toString("utf8");
I found a useful function present in web3 library.
var hexString = "0x1231ac"
string strValue = web3.toAscii(hexString)
Update: Newer version of web3 has this function in utils
The functions now resides in utils:
var hexString = "0x1231ac"
string strValue = web3.utils.hexToAscii(hexString)
I've found that the above solution will not work if you have to deal with control characters like 02 (STX) or 03 (ETX), anything under 10 will be read as a single digit and throw off everything after. I ran into this problem trying to parse through serial communications. So, I first took the hex string received and put it in a buffer object then converted the hex string into an array of the strings like so:
buf = Buffer.from(data, 'hex');
l = Buffer.byteLength(buf,'hex');
for (i=0; i<l; i++){
char = buf.toString('hex', i, i+1);
msgArray.push(char);
}
Then .join it
message = msgArray.join('');
then I created a hexToAscii function just like in #Delan Azabani's answer above...
function hexToAscii(str){
hexString = str;
strOut = '';
for (x = 0; x < hexString.length; x += 2) {
strOut += String.fromCharCode(parseInt(hexString.substr(x, 2), 16));
}
return strOut;
}
then called the hexToAscii function on 'message'
message = hexToAscii(message);
This approach also allowed me to iterate through the array and slice into the different parts of the transmission using the control characters so I could then deal with only the part of the data I wanted.
Hope this helps someone else!
console.log(
"68656c6c6f20776f726c6421".match(/.{1,2}/g).reduce((acc,char)=>acc+String.fromCharCode(parseInt(char, 16)),"")
)
An optimized version of the implementation of the reverse function proposed by #michieljoris (according to the comments of #Beterraba and #Mala):
function a2hex(str) {
var hex = '';
for (var i = 0, l = str.length; i < l; i++) {
var hexx = Number(str.charCodeAt(i)).toString(16);
hex += (hexx.length > 1 && hexx || '0' + hexx);
}
return hex;
}
alert(a2hex('2460')); // display 32343630
I use this one, it seems more clear to me as I also receive data with spaces like '30 31 38 30 38 30' and the output is 018080
hexToString(hex: string): string {
return hex.split(' ').map(s => string.fromCharCode(parseInt(s,16))).join('');
}
I am new to javascript, i tried to modify a text shown below with substring command.
eg. "ABCD_X_DD_text" into "ABCD-X(DD)_text" this
i used this
var str = "ABCD_X_DD_cover";
var res = str.substring(0,4)+"-"+str.substring(5,6)+"("+str.substring(7,9)+")"+str.substring(9,15);
// print to console
console.log(res);
i got what i want. But problem is X and DD are numerical (digit) value. and they are changeable. here my code just stop working.
it can be ..... "ABCD_XXX_DDDD_text" or "ABCD_X_DDD_text".
could you suggest some code, which works well in this situation.
You can use a split of the words.
var strArray = [
"ABCD_X_DD_cover",
"ABCD_XX_DD_cover",
"ABCD_XXX_DD_cover"
];
for(var i = 0; i < strArray.length; i++){
var split = strArray[i].split("_");
var str = split[0] + "-" + split[1] + "(" + split[2] + ") " + split[3];
console.log(str);
}
I used a for cycle using an array of strings, but you can do it with a variable too.
so I need to be able to enter a string and have it reversed. I must have one library JS file and one regular JS file. Here is my library JS file:
function reverseString(string) {
var reversedString= "";
for(var i = string.length -; i >=; --i) {
reversedString = reversedString + string[i];
}
return reversedString;
}
and here is my regular one
var stringEntered = prompt("Enter a string:")
var newString = reverseString(stringEntered);
document.write("the reverse of the string \" + stringEntered + \ " is \" + newString + ".")
I entered it the exact same way my professor showed us, and I when I try to run my HTML file (which is coded to call both these files), nothing happens. What am I missing?
There're a lot of syntax issues. Here's a working code:
function reverseString(string) {
var reversedString = "";
// This loop had a lot of basic syntax issues and also
// "i" was starting from the length value, while a string
// is a character array and array indexes start from 0 instead of 1
for (var i = string.length - 1; i >= 0; --i) {
reversedString = reversedString + string[i];
}
return reversedString;
}
var stringEntered = prompt("Enter a string:");
var newString = reverseString(stringEntered);
// Here I found a mess of "/" characters
// I've changed the horrible document.write with alert so you can check the result without opening the debugger...
alert("the reverse of the string " + stringEntered + " is " + newString + ".")
Here is a concise method of reversing a string:
function reverseString(string) {
return string.split('').reverse().join('');
}
var str = prompt("Enter a string", "a racecar dad");
alert(reverseString(str));
Turn it into an array, reverse the array, turn it back into a string.
Edit: Sorry, didn't see #SidneyLiebrand's comment telling you to do the same.
I am trying to break up this string by first splitting it into sections divided by ';'. Then I want to split those sections divided by ','. It is not working though and I am about to break my computer. Could someone please help me figure this out.
You can play around with my jsfiddle if you want... http://jsfiddle.net/ChaZz/
var myString = "Call 1-877-968-7762 to initiate your leave.,-30,0,through;You are eligible to receive 50% pay.,0,365,through;Your leave will be unpaid.,365,0,After;";
var mySplitResult = myString.split(";");
for(i = 0; i < mySplitResult.length -1; i++){
var mySplitResult2 = i.split(",");
for(z = 0; z < mySplitResult2.length -1; i++) {
//document.write("<br /> Element " + i + " = " + mySplitResult[i]);
document.write("<br/>Element" + z + " = " + mySplitResult[z]);
}
}
i is a number, as that's how you defined it.
To split the string, you need to access the i member of the Array.
var mySplitResult2 = mySplitResult[i].split(",");
If I may, if you have to split with character a then character b, the simplest would be :
string.split('a').join('b').split('b')
How to convert from Hex string to ASCII string in JavaScript?
Ex:
32343630 it will be 2460
function hex2a(hexx) {
var hex = hexx.toString();//force conversion
var str = '';
for (var i = 0; i < hex.length; i += 2)
str += String.fromCharCode(parseInt(hex.substr(i, 2), 16));
return str;
}
hex2a('32343630'); // returns '2460'
Another way to do it (if you use Node.js):
var input = '32343630';
const output = Buffer.from(input, 'hex');
log(input + " -> " + output); // Result: 32343630 -> 2460
For completeness sake the reverse function:
function a2hex(str) {
var arr = [];
for (var i = 0, l = str.length; i < l; i ++) {
var hex = Number(str.charCodeAt(i)).toString(16);
arr.push(hex);
}
return arr.join('');
}
a2hex('2460'); //returns 32343630
You can use this..
var asciiVal = "32343630".match(/.{1,2}/g).map(function(v){
return String.fromCharCode(parseInt(v, 16));
}).join('');
document.write(asciiVal);
** for Hexa to String**
let input = '32343630';
Note : let output = new Buffer(input, 'hex'); // this is deprecated
let buf = Buffer.from(input, "hex");
let data = buf.toString("utf8");
I found a useful function present in web3 library.
var hexString = "0x1231ac"
string strValue = web3.toAscii(hexString)
Update: Newer version of web3 has this function in utils
The functions now resides in utils:
var hexString = "0x1231ac"
string strValue = web3.utils.hexToAscii(hexString)
I've found that the above solution will not work if you have to deal with control characters like 02 (STX) or 03 (ETX), anything under 10 will be read as a single digit and throw off everything after. I ran into this problem trying to parse through serial communications. So, I first took the hex string received and put it in a buffer object then converted the hex string into an array of the strings like so:
buf = Buffer.from(data, 'hex');
l = Buffer.byteLength(buf,'hex');
for (i=0; i<l; i++){
char = buf.toString('hex', i, i+1);
msgArray.push(char);
}
Then .join it
message = msgArray.join('');
then I created a hexToAscii function just like in #Delan Azabani's answer above...
function hexToAscii(str){
hexString = str;
strOut = '';
for (x = 0; x < hexString.length; x += 2) {
strOut += String.fromCharCode(parseInt(hexString.substr(x, 2), 16));
}
return strOut;
}
then called the hexToAscii function on 'message'
message = hexToAscii(message);
This approach also allowed me to iterate through the array and slice into the different parts of the transmission using the control characters so I could then deal with only the part of the data I wanted.
Hope this helps someone else!
console.log(
"68656c6c6f20776f726c6421".match(/.{1,2}/g).reduce((acc,char)=>acc+String.fromCharCode(parseInt(char, 16)),"")
)
An optimized version of the implementation of the reverse function proposed by #michieljoris (according to the comments of #Beterraba and #Mala):
function a2hex(str) {
var hex = '';
for (var i = 0, l = str.length; i < l; i++) {
var hexx = Number(str.charCodeAt(i)).toString(16);
hex += (hexx.length > 1 && hexx || '0' + hexx);
}
return hex;
}
alert(a2hex('2460')); // display 32343630
I use this one, it seems more clear to me as I also receive data with spaces like '30 31 38 30 38 30' and the output is 018080
hexToString(hex: string): string {
return hex.split(' ').map(s => string.fromCharCode(parseInt(s,16))).join('');
}