I am posting back a string from c# to JavaScript;
The string received looks like this:
arr = "[["A","B","C"],["D","E","F"]]";
I want to pass this to a function to create a table body in HTML but JavaScript always reads this as a string of chars NOT as an array - even when I use Array.from in example below:
CreatePositionsBodt(arr);
function CreatePositionsBodt(arr) {
alert(arr);
var asArr = Array.from(arr); function
}
change the surrounding quotes to apostrophe var arr = '[["A","B","C"],["D","E","F"]]';
and use eval() or JSON.parse()
var arr = '[["A","B","C"],["D","E","F"]]';
var myArray = eval(arr);
or
var arr = '[["A","B","C"],["D","E","F"]]';
var myArray = JSON.parse(arr);
note: if you have not done so in previous invisible lines of code, use var
Related
I have not been coding for long and ran into my first issue I just can not seem to figure out.
I have a string "XX|Y1234$ZT|QW4567" I need to remove both $ and | and push it into an array like this ['XX', 'Y1234', 'ZT', 'QW4567'].
I have tried using .replace and .split in every way I could like of
var array = "XX|Y1234$ZT|QW4567"
var array2 = [];
array = array.split("$");
for(i = o; i <array.length; i++)
var loopedArray = array[i].split("|")
loopedArray.push(array2);
}
I have tried several other things but would take me awhile to put them all down.
You can pass Regex into .split(). https://regexr.com/ is a great tool for messing with Regex.
// Below line returns this array ["XX", "Y1234", "ZT", "QW4567"]
// Splits by $ and |
"XX|Y1234$ZT|QW4567".split(/\$|\|/g);
Your code snippet is close, but you've messed up your variables in the push statement.
var array = "XX|Y1234$ZT|QW4567"
var array2 = [];
array = array.split("$");
for (i = 0; i < array.length; i++) {
var loopedArray = array[i].split("|")
array2.push(loopedArray);
}
array2 = array2.flat();
console.log(array2);
However, this can be rewritten much cleaner using flatMap. Also note the use of let instead of var and single quotes ' instead of double quotes ".
let array = 'XX|Y1234$ZT|QW4567'
let array2 = array
.split('$')
.flatMap(arrayI => arrayI.split('|'));
console.log(array2);
And lastly, split already supports multiple delimiters when using regex:
let array = 'XX|Y1234$ZT|QW4567'
let array2 = array.split(/[$|]/);
console.log(array2);
You can do this as follows:
"XX|Y1234$ZT|QW4567".replace('$','|').split('|')
It will produce the output of:
["XX", "Y1234", "ZT", "QW4567"]
If you call the split with two parameters | and the $ you will get an strong array which is splittend by the given characters.
var array = "XX|Y1234$ZT|QW4567";
var splittedStrings = array.Split('|','$');
foreach(var singelString in splittedStrings){
Console.WriteLine(singleString);
}
the output is:
XX
Y1234
ZT
QW4567
I have this:
var myarray = [];
myarray ["first"] = "$firstelement";
myarray ["second"] = "$secondelement";
And I want to get the string:
"first":"$firstelement","second": "$secondelement"
How can I do it?
What you have is invalid (even if it works), arrays don't have named keys, but numeric indexes.
You should be using an object instead, and if you want a string, you can stringify it as JSON
var myobject = {};
myobject["first"] = "$firstelement";
myobject["second"] = "$secondelement";
var str = JSON.stringify(myobject);
console.log(str)
First of all, you'd want to use an object instead of an array:
var myarray = {}; // not []
myarray ["first"] = "$firstelement";
myarray ["second"] = "$secondelement";
The easiest way, then, to achieve what you want is to use JSON:
var jsonString = JSON.stringify(myarray);
var arrayString = jsonString.slice(1, -1);
JSON.stringify() method converts a JavaScript value to a JSON string, optionally replacing values if a replacer function is specified, or optionally including only the specified properties if a replacer array is specified.
var myarray = {};
myarray ["first"] = "$firstelement";
myarray ["second"] = "$secondelement";
console.log(JSON.stringify(myarray));
Use JSON.strinify()
JSON.stringify(item)
I have this type of list from javascript:
Amila,Asanka,Imaad,Kelum,Lakshan,Sagara,Thilina
I used the following code to convert to my output
var array = columnsload.split(",");
var string = JSON.stringify(columnsload);
var nameArray = string.split(',');
The output is like this :
"Amila,Asanka,Imaad,Kelum,Lakshan,Sagara,Thilina"
But I really need it like this :
["Amila","Asanka","Imaad","Kelum","Lakshan","Sagara","Thilina"]
Anyone know how to get output like this?
the split function is enough to convert the string into an array;
var names = "Amila,Asanka,Imaad,Kelum,Lakshan,Sagara,Thilina";
var nameArr = names.split(",");
console.log( nameArr );
http://www.w3schools.com/jsref/jsref_split.asp
Just do var nameArray = columnsload.split(',');. You dont need to stringify the array and then split it again, just one .split would be enough.
var columnsload = "Amila,Asanka,Imaad,Kelum,Lakshan,Sagara,Thilina";
var nameArray = columnsload.split(',');
console.log(nameArray);
If you need the whole thing to be string, you can run a JSON.stringify on the array after.
var columnsload = "Amila,Asanka,Imaad,Kelum,Lakshan,Sagara,Thilina";
var nameArray = columnsload.split(',');
console.log(JSON.stringify(nameArray));
// outputs ["Amila","Asanka","Imaad","Kelum","Lakshan","Sagara","Thilina"]
// as one string.
This is a really stupid question, but I'm just drawing a blank here...
What type of variable declaration is this:
var s1 = [1,2,3,4]
Also, How can I construct a variable like this from multiple objects when the amount of those objects is unknown. This is what I came up with, which doesn't work.
var s1 = [];
for(x in data[i].uh) {
s1 += data[i].uh[x];
}
var s1 = [1,2,3,4]
is an array declaration of four integers using "Array Literal Notation"
You don't need a loop to copy the array, simply do this:
var s1 = data.slice(0);
or in your example you might want this:
var s1 = data[i].uh.slice(0);
Read more about copying arrays here: http://my.opera.com/GreyWyvern/blog/show.dml/1725165
"The slice(0) method means, return a
slice of the array from element 0 to
the end. In other words, the entire
array. Voila, a copy of the array."
That is called an Array, which can be declared with new Array() or by using the array literal [] as in your example. You can use the Array.push() method (see docs) to add a new value to it:
var s1 = [];
for(x in data[i].uh) {
s1.push(data[i].uh[x]);
}
This
var s1 = [1,2,3,4]
is an array declaration.
To add an element to an array, use the push method:
var s1 = [];
for(x in data[i].uh) {
s1.push(data[i].uh[x]);
}
s1 is an array, it's a proper Javascript object with functions.
var s1 = [];
is the recommend way to create an array. As opposed to:
var s1 = new Array();
(see: http://www.hunlock.com/blogs/Mastering_Javascript_Arrays)
To add items to an array use s1.push(item) so your code would be:
var s1 = [];
for(x in data[i].uh) {
s1.push(data[i].uh[x]);
}
As a side note, I wouldn't recommend using for-in, at least not without checking hasOwnProperty.
It's declaring a local variable with an Array with 4 members.
If you want to append to an Array, use the push() method.
That is an array. To add to arrays you would use Array.push(). For example:
var s1 = [];
s1.push(1);
s1.push(2);
I have an ajax request that returns a list of values like this:
"1,2,3,4,5,6"
I need it to be a javascript array with numbers:
[1,2,3,4,5,6]
I tried:
var array = new Array("1,2,3,4,5,6".split(","))
But the numbers are still strings in the output:
["1","2","3","4","5","6"]
Is there a clean way to have it as a numbered array? Preferably without writing a function to iterate through it?
You need to loop through and convert them to numbers, like this:
var array = "1,2,3,4,5,6".split(",");
for(var i=0; i<array.length; i++) array[i] = +array[i];
Or, the more traditional example:
var array = "1,2,3,4,5,6".split(",");
for(var i=0; i<array.length; i++) array[i] = parseInt(array[i], 10);
A more jQuery-centric approach using jQuery.map():
var str = "1,2,3,4,5,6";
var arr = $.map(str.split(","), function(el) { return parseInt(el, 10); });
Not sure if this counts as writing a function but you can use the map function in jquery. I saw you listed as a tag so I assume you are using:
var stringArray = "1,2,3,4,5,6".split(",");
var numberArray = $.map(stringArray,
function(item, i)
{
return parseInt(item, 10);
});
// jquery must have a way to do what any modern browser can do:
var str= "1,2,3,4,5,6";
var arr= str.split(',').map(Number);
// returns an array of numbers
If you trust the ajax response, and if (for whatever reason) you're committed to not using a loop, you can always go with eval:
var str = "1,2,3,4,5,6";
var array = eval("[" + str + "]");
If you don't wish to expliclty iterate you can use array.map, javascripts map function.
array.map(callbackFunc, array);
var arr = array.map(function(x) {return parseInt(x);}, "1,2,3,4,5,6".split(","));
http://www.tutorialspoint.com/javascript/array_map.htm
Theres probably a better reference somewhere but I don't us javascript enough to have a good favorite reference site.
EDIT - i see jQuery has its own map, thats probably worth looking into.