What is the most efficient way to insert one Vector into another at specific position?
For example:
var aa:Vector.<int> = Vector.<int>([1, 2, 3]);
var bb:Vector.<int> = Vector.<int>([9, 8, 7]);
This doesn't seems to work:
bb.splice(1, 0, aa);
The result is [9, 0, 8, 7].
For the moment there is no builtin function other than doing a loop over the Vector, here two methods (i have not timed them).
If bb can be a new Vector you can do for example:
var insertIndex:int = 1;
bb=bb.slice(0, insertIndex).concat(aa).concat(bb.slice(insertIndex));
If bb cannot be change you can do a splice but with preparing the elements to insert into a new Array:
var insertIndex:int = 1;
var parms:Array=[insertIndex, 0]; // prepare the arguments for the splice call
var j:int = 2; // length of the parms array
var len:int = aa.length;
for (var i:int = 0; i < len; i++, j++){
parms[j] = aa[i];
}
// call the splice with the new arguments
bb.splice.apply(bb, parms);
If you need to concat one after the other, as PatrickS mentionned bb.concat will do the job.
If you need to insert values in the middle you'll need something like
for each (var i : int in aa.reverse())
{
bb.splice(1,0,i);
}
or, more elegantly, this, if you cannot change aa
var insertingIndex : int = 2;
for each ( var i : int in aa )
{
bb.splice( insertingIndex, 0, i );
insertingIndex++;
}
Related
I have a problem when I'm trying to a loop in a DataTable that a dataset contains.
I'm doing a loop like this:
for(int i = 0; i<ds.Tables[0].Rows.Count - 1 ; i++)
The problem is that I can't get the value of the last line with this one, but if I try to get rid of the "-1" and do a loop on the whole table, I'll have an out of range exception.
This out of range exception is because I have to check if the value of a line "i" is equal to the value of a line "i+1", like this:
if (ds.Tables[0].Rows[i]["Release_No"] != ds.Tables[0].Rows[i + 1]["Release_No"])
So if I do it in a loop, when the index is on the last line it will check if the last line is equal to i+1, and it's out of the table.
So I was trying to check if the index is on the last line, then just get the value of the last line, but it seems like it doesn't work.
if(ds.Tables[0].Rows.IndexOf(ds.Tables[0].Rows[i]) == ds.Tables[0].Rows.Count)
If anyone has an idea, let me know, and of course if it is not clear enough let me know, I'll give more information and more code.
Thanks for your help and your time!
Check if it's the last record, first.
I like to refactor code to read as close to sentence form as possible, explaining what you want it to do using named variables and methods, and that often gets me unlocked.
Try to make each line of code do one thing, and one thing only, like check if it is the last row:
var data = ds.Tables[0].Rows;
var lastRow = data.Count - 1;
for(int i = 0; i < lastRow ; i++)
{
if (i == lastRow){
// This is the last row. Handle the last row here.
}
else
{
// Handle all other rows here
var currentRecord = data[i];
var nextRecord = data[i + 1];
if (currentRecord["Release_No"] != nextRecord["Release_No"])
{
// Handle unique Releases...
}
}
}
Use less than or equal to like this
for(int i = 0; i<=ds.Tables[0].Rows.Count - 1 ; i++)
I hope this may get what you want.
Something like this is better ?
var lastRow = data.Count - 1;
var data = ds.Tables[0].Rows;
for(int i = 0; i< lastRow; i++)
{
testFirstCum = Convert.ToInt32(ds.Tables[0].Rows[i]["EDI_Accum_Quantity"]);
if ( i == lastRow)
{
if (DBNull.Value.Equals(data[i]))
{
quantity = 0;
}
else
{
quantity = Convert.ToInt32(data[i]);
testFirstCum = testFirstCum + quantity;
System.Diagnostics.Debug.WriteLine(quantity);
System.Diagnostics.Debug.WriteLine(testFirstCum);
}
}
else
{
var col = ds.Tables[0].Columns;
var currentRecord = data[i];
var nextRecord = data[i + 1];
if(currentRecord["Release_No"] != nextRecord["Release_No"])
{
for (int j = col[2].Ordinal; j < col.Count; j++)
{
if (DBNull.Value.Equals(data[i][j]))
{
quantity = 0;
}
else
{
quantity = Convert.ToInt32(data[i][j]);
testFirstCum = testFirstCum + quantity;
System.Diagnostics.Debug.WriteLine(quantity);
System.Diagnostics.Debug.WriteLine(testFirstCum);
}
}
}
}
}
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('');
}
Say for example, I have an XML file with 100 "person" nodes, and I want the first 30. Or possibly 51 - 100. Is there any way to do this with e4x syntax to return an XMLList?
var list:XMLList = xml.person;
var start:int = 10;
var end:int = 40;
var filteredList:XMLList = new XMLList();
for(i = start - 1; i < end; i++)
filteredList += new XML(XML(list[i]).toXMLString());
How can I access the member variable of an object by using a variable in the name.
Example:
Entries Object has properties 1, 2, 3, 4, 5.
Normally I would access them by
var i : int = Entries.1;
var i : int = Entries.2;
However, if I have a loop
for (var j : int = 1; j < 6; j++){
trace(Entries[j]);
}
does not work.
Entries.(j)
Entries.j
neither.
What's the way to go?
Entries.hasOwnProperty("j")
also does not work to check if the member exists.
Thanks!
Entries.hasOwnProperty("j")
does not work because you're sending it "j" as a string, you need to convert the integer variable j to a string, therefore representing the number you are looking for. Eg:
Entries.hasOwnProperty(j.toString());
So to extract the property from your object, you can do:
for(var j:int = 1; j < 6; j++)
{
trace(Entries[j.toString()]);
}
How do you convert a decimal number to mixed radix notation?
I guess that given an input of an array of each of the bases, and the decimal number, it should output an array of the values of each column.
Pseudocode:
bases = [24, 60, 60]
input = 86462 #One day, 1 minute, 2 seconds
output = []
for base in reverse(bases)
output.prepend(input mod base)
input = input div base #div is integer division (round down)
Number -> set:
factors = [52,7,24,60,60,1000]
value = 662321
for i in n-1..0
res[i] = value mod factors[i]
value = value div factors[i]
And the reverse:
If you have the number like 32(52), 5(7), 7(24), 45(60), 15(60), 500(1000) and you want this converted to decimal:
Take number n, multiply it with the factor of n-1, continue for n-1..n=0
values = [32,5,7,45,15,500]
factors = [52,7,24,60,60,1000]
res = 0;
for i in 0..n-1
res = res * factors[i] + values[i]
And you have the number.
In Java you could do
public static int[] Number2MixedRadix(int[] base, int number) throws Exception {
//NB if the max number you want # a position is say 3 then the base# tha position
//in your base array should be 4 not 3
int[] RadixFigures = new int[base.length];
int[] PositionPowers = new int[base.length];
PositionPowers[base.length-1] = 1;
for (int k = base.length-2,pow = 1; k >-1; k--){
pow*=base[k+1];
PositionPowers[k]=pow;
}for (int k = 0; k<base.length; k++){
RadixFigures[k]=number/PositionPowers[k];
if(RadixFigures[k]>base[k])throw new Exception("RadixFigure#["+k+"] => ("+RadixFigures[k]+") is > base#["+k+"] => ("+base[k]+") | ( number is Illegal )");
number=number%PositionPowers[k];
}return RadixFigures;
}
Example
//e.g. mixed-radix base for 1day
int[] base = new int[]{1, 24, 60, 60};//max-day,max-hours,max-minutes,max-seconds
int[] MixedRadix = Number2MixedRadix(base, 19263);//19263 seconds
//this would give [0,5,21,3] => as per 0days 5hrs 21mins 3secs
Reversal
public static int MixedRadix2Number(int[] RadixFigures,int[] base) throws Exception {
if(RadixFigures.length!=base.length)throw new Exception("RadixFigures.length must be = base.length");
int number=0;
int[] PositionPowers = new int[base.length];
PositionPowers[base.length-1] = 1;
for (int k = base.length-2,pow = 1; k >-1; k--){
pow*=base[k+1];
PositionPowers[k]=pow;
}for (int k = 0; k<base.length; k++){
number+=(RadixFigures[k]*PositionPowers[k]);
if(RadixFigures[k]>base[k])throw new Exception("RadixFigure#["+k+"] => ("+RadixFigures[k]+") is > base#["+k+"] => ("+base[k]+") | ( number is Illegal )");
}return number;
}
I came up with a slightly different, and probably not as good method as the other ones here, but I thought I'd share anyway:
var theNumber = 313732097;
// ms s m h d
var bases = [1000, 60, 60, 24, 365];
var placeValues = []; // initialise an array
var currPlaceValue = 1;
for (var i = 0, l = bases.length; i < l; ++i) {
placeValues.push(currPlaceValue);
currPlaceValue *= bases[i];
}
console.log(placeValues);
// this isn't relevant for this specific problem, but might
// be useful in related problems.
var maxNumber = currPlaceValue - 1;
var output = new Array(placeValues.length);
for (var v = placeValues.length - 1; v >= 0; --v) {
output[v] = Math.floor(theNumber / placeValues[v]);
theNumber %= placeValues[v];
}
console.log(output);
// [97, 52, 8, 15, 3] --> 3 days, 15 hours, 8 minutes, 52 seconds, 97 milliseconds
I tried a few of the examples before and found an edge case they didn't cover, if you max out your scale you need to prepend the result from the last step
def intToMix(number,radix=[10]):
mixNum=[]
radix.reverse()
for i in range(0,len(radix)):
mixNum.append(number%radix[i])
number//=radix[i]
mixNum.append(number)
mixNum.reverse()
radix.reverse()
return mixNum
num=60*60*24*7
radix=[7,24,60,60]
tmp1=intToMix(num,radix)