Handling multidimentional array in java script is not working - javascript

function split(str)
{
var array = str.split(';');
var test[][] = new Array();
for(var i = 0; i < array.length; i++)
{
var arr = array[i].split(',');
for(var j = 0; j < arr.length; j++)
{
test[i][j]=arr[j];
}
}
}
onchange="split('1,2,3;4,5,6;7,8,9;a,b,c;d,e,f;g,h,i')"
it was not working. i need to split this string to 6*3 multi dimentional array

var array[][] = new Array() is not valid syntax for declaring arrays. Javascript arrays are one dimensional leaving you to nest them. Which means you need to insert a new array into each slot yourself before you can start appending to it.
Like this: http://jsfiddle.net/Squeegy/ShWGB/
function split(str) {
var lines = str.split(';');
var test = [];
for(var i = 0; i < lines.length; i++) {
if (typeof test[i] === 'undefined') {
test[i] = [];
}
var line = lines[i].split(',');
for(var j = 0; j < line.length; j++) {
test[i][j] = line[j];
}
}
return test;
}
console.log(split('a,b,c;d,e,f'));

var test[][] is an invalid javascript syntax.
To create a 2D array, which is an array of array, just declare your array and push arrays into it.
Something like this:
var myArr = new Array(10);
for (var i = 0; i < 10; i++) {
myArr[i] = new Array(20);
}
I'll let you apply this to your problem. Also, I don't like the name of your function, try to use something different from the standards, to avoid confusion when you read your code days or months from now.

function split(str)
{
var array = str.split(';'),
length = array.length;
for (var i = 0; i < length; i++) array[i] = array[i].split(',');
return array;
}
Here's the fiddle: http://jsfiddle.net/AbXNk/

var str='1,2,3;4,5,6;7,8,9;a,b,c;d,e,f;g,h,i';
var arr=str.split(";");
for(var i=0;i<arr.length;i++)arr[i]=arr[i].split(",");
Now arr is an array with 6 elements and each element contain array with 3 elements.
Accessing element:
alert(arr[4][2]); // letter "f" displayed

Related

Javascript array with index and multiple items on it

I've to do a strange thing and I don't know if is possible.
Let assume I've one aray
MasterArray = [1,2,3,4];
Now for each MasterArray item I need to have multiple insertion, for example under the item 1 I've to push N value, for example the MasterArray[0] must have this correlations
5,8,3,9 ...
This for any items on MasterArray.
My first idea is to create a new array one for each MasterArray items, something like this
var newobject = X;
for (i = 0; i < MasterArray.length; i++) {
Arr[i] = push the newobject ;
}
But I don't think that is a good way!
The purpose it to have a kind of correlated array.
MasterArray[0] is correlated to another array [5,8,3,9, ...]
MasterArray[1] is correlated to another array [5,6,7,1, ...]
MasterArray[2] is correlated to another array [7,45,23,2, ...]
And so on
I hope to have explained myself
Just create a 2D array in this way:
var myArray = new Array(5); // For example 5;
for (var i = 0; i < myArray.length; i++) {
myArray[i] = new Array(10);
}
Or, if you don't need to specify any size:
var myArray = new Array(5); // For example 5;
for (var i = 0; i < myArray.length; i++) {
myArray[i] = [];
}
EDIT:
For manipulate you just need to use innested loops:
for (var i = 0; i < myArray.length; i++) {
for (var j = 0; i < myArray[i].length; j++) {
myArray[i][j] = x; // where x is some variable
}
For add elements in the back just use .push() method:
myArray[0].push(5);

Initializing the 2D array elements in javascript

I want to initialize and then print the elements of a 2D array using javascript.
I wrote this code but nothing displays as output. How to output this array?
var m = 6;
var n = 3;
var mat = new Array[m][n];
for (i = 0; i < mat.length; i++) {
for (j = 0; j < mat[i].length; j++) {
mat[i][j]) = i * j;
document.writeln(mat[i][j]);
}
document.writeln("<br />");
}
<html>
<body>
</body>
<script>
var m=6;
var n=3;
var mat =new Array(m);
for( var i=0; i < m ; i++){
mat[i] = new Array(n);
for( var j=0;j< n ;j++){
mat[i][j] = i*j;
document.writeln(mat[i][j]);
}
document.writeln("<br />");
}
</script>
</html>
As BenG pointed out, you've got an extra ) but you also aren't initializing your array correctly. Javascript doesn't allow you to declare multi-dimensional arrays like other languages. Instead, you'd have to do something more like this:
var m = 6;
var n = 3;
var mat = new Array(m);
for (var i = 0; i < m; i++) {
mat[i] = new Array(n);
}
Javascript arrays are dynamic. They will grow to the size you require. You can call push() to add a new element to the array. It's also worth noting that you should avoid using the new keyword with objects and arrays. Use their literal notations [] for arrays and {} for objects. So a better solution here would be to push to the arrays as you need them.
var mat = [];
var m = 6;
var n = 3;
for (var i = 0; i < m; i++) {
// Let's add an empty array to our main array
mat.push([]);
for (var j = 0; j < n; j++) {
mat[i].push(i * j);
document.writeln(i * j);
}
document.writeln('<br />');
}

Creating a function to create multiple arrays with the same properties

I want to create multiple arrays that contain the same basic layout. Currently, i have
Array(10); //base array with moving blocks
for(var i = 0; i < 10; i++){ //creating an array within an array (2d)
base[i] = new Array(22);
}
var background = new Array(10); //background array with stationary blocks
for(var z = 0; z < 10; z++){ //same as before
background[z] = new Array(22);
}
var nextBlock = new Array(10); //next block array
for(var i = 0; i <10; i++){
nextBlock[i] = new Array(22);
}
and would like to have something similar to:
function arrayCreator(rows,cols){
var array = newArray(rows);
for(var i = 0;i < rows;i++){
array[i] = newArray(cols);
}
}
var base = arrayCreator(10,22);
var background = arrayCreator(10,22);
var nextBlock = arrayCreator(10,22);
but cant get it working. How should I approach this?
Looks like you forgot the return statement.
function arrayCreator(rows,cols){
var array = newArray(rows);
for(var i = 0;i < rows;i++){
array[i] = newArray(cols);
}
return array;
}

splitting a string based on delimiter using javascript

Hi I'm trying to split a string based on multiple delimiters.Below is the code
var data="- This, a sample string.";
var delimiters=[" ",".","-",","];
var myArray = new Array();
for(var i=0;i<delimiters.length;i++)
{
if(myArray == ''){
myArray = data.split(delimiters[i])
}
else
{
for(var j=0;j<myArray.length;j++){
var tempArray = myArray[j].split(delimiters[i]);
if(tempArray.length != 1){
myArray.splice(j,1);
var myArray = myArray.concat(tempArray);
}
}
}
}
console.log("info","String split using delimiters is - "+ myArray);
Below is the output that i get
a,sample,string,,,,This,
The output that i should get is
This
a
sample
string
I'm stuck here dont know where i am going wrong.Any help will be much appreciated.
You could pass a regexp into data.split() as described here.
I'm not great with regexp but in this case something like this would work:
var tempArr = [];
myArray = data.split(/,|-| |\./);
for (var i = 0; i < myArray.length; i++) {
if (myArray[i] !== "") {
tempArr.push(myArray[i]);
}
}
myArray = tempArr;
console.log(myArray);
I'm sure there's probably a way to discard empty strings from the array in the regexp without needing a loop but I don't know it - hopefully a helpful start though.
Here you go:
var data = ["- This, a sample string."];
var delimiters=[" ",".","-",","];
for (var i=0; i < delimiters.length; i++) {
var tmpArr = [];
for (var j = 0; j < data.length; j++) {
var parts = data[j].split(delimiters[i]);
for (var k = 0; k < parts.length; k++) {
if (parts[k]) {
tmpArr.push(parts[k]);
}
};
}
data = tmpArr;
}
console.log("info","String split using delimiters is - ", data);
Check for string length > 0 before doing a concat , and not != 1.
Zero length strings are getting appended to your array.

Create arrays dynamically in a loop with javascript

Here's a pseudocode example about what I'm trying to do:
var totalLanguages = XX;
for(var i = 0; i < totalLanguages; i++){
var dynamicArray + i = new Array();
/*.....*/
}
I need to create dynamically many arrays as the value of totalLanguages which can be either number.
This is to be able to do something like this:
for(var i = 0; i < totalLanguages; i++){
var arrayLanguages["es"] = dynamicArray+i;
var arrayLanguages["en"] = dynamicArray+i;
}
Is there any way to do this?
var languageNames = ['en', 'es'];
var languages = {};
for (var i = 0; i < languageNames.length; i++) {
languages[languageNames[i]] = [];
}
You are basically trying to recreate an array with variable names. Just use an Array to start out!
var dynamicArray = [];
for(var i = 0; i < totalLanguages; i++) {
dynamicArray[i] = new Array();
}
You can use multi-dimensional arrays:
var languagesArray = new Array(totalLanguages);
for(var i = 0; i < totalLanguages; i++) {
var innerArray = new Array();
innerArray.push("Hello");
innerArray.push("World");
languagesArray[i] = innerArray;
}
console.log(languagesArray[0][0]);
See: How can I create a two dimensional array in JavaScript?
How about:
for(var i = 0; i < totalLanguages; i++){
window["dynamicvariable " + i] = new Array();
/*.....*/
}

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