How would you convert this string to JSON? - javascript

I need to serialize this string into a multidimensional array using JSON. How would you do it?
{frmb[0][cssClass]=textarea&frmb[0][required]=true&frmb[0][values]=para&frmb[1][cssClass]=radio&frmb[1][required]=true&frmb[1][title]=rdo&frmb[1][values][2][value]=one&frmb[1][values][2][baseline]=true&frmb[1][values][3][value]=two&frmb[1][values][3][baseline]=false&frmb[2][cssClass]=input_text&frmb[2][required]=false&frmb[2][values]=text&frmb[3][cssClass]=checkbox&frmb[3][required]=true&frmb[3][title]=chk&frmb[3][values][2][value]=chk+1&frmb[3][values][2][baseline]=true&frmb[3][values][3][value]=chk+2&frmb[3][values][3][baseline]=false&frmb[4][cssClass]=select&frmb[4][required]=false&frmb[4][multiple]=true&frmb[4][title]=sel&frmb[4][values][2][value]=sel1&frmb[4][values][2][baseline]=true&frmb[4][values][3][value]=sel2&frmb[4][values][3][baseline]=false&form_id=undefined}
EDIT:
The multidimensionality is really screwing me up on converting this string into JSON. I tried stripping out the brackets to get a list of indices for the array, but rebuilding the array in a useful manner has been the biggest challenge.
So I have been doing:
private static List<string> StripBrackets(string input)
{
var ret = new List<string>();
var indx = 0;
do
{
input = input.TrimStart('[');
indx = input.IndexOf(']');
if(indx !=-1)
{
var newVal = input.Substring(0, indx);
ret.Add(newVal);
input = input.Remove(0, indx+1);
}
} while (indx != -1);
//-- this is where I bonked
string[,] results = new string[ret.Count, 23];
foreach (var r in ret)
{
}
return ret;
}
I've been grinding on this for a long time - hence the tired/limited question. It started to feel like I was doing this the "hard way" and wanted to see if anyone enlightened had any better ideas. TIA

Expanding on #ratchetfreak's comment:
var str = "{frmb...";
//sanitize string
str = str.substring(1, str.length-1); //remove braces
str = str.replace(/\[([a-z]+)\]/gi, '["$1"]'); //enclose non-numeric keys in double quotes
str = str.replace(/=([^&]+)/g, '="$1"'); //enclose values in double quotes
str = str.replace(/"(true|false)"/g, "$1"); //remove double quotes around boolean values
str = str.replace(/&/g, ";"); //replace all ampersands with semi-colons
//initialize "frmb"
var frmb = [];
for (var i = 0; i < 5 /* a guess as to how long "frmb" will be */; i++){
var values = [];
for (var j = 0; j < 5 /* a guess as to how long each "values" field will be */; j++){
values.push({});
}
frmb.push({values:values});
}
//evaluate as Javascript
eval(str);
//marshal to string
var result = JSON.stringify(frmb);
The part that makes this solution difficult to make general-purpose is that you need to initialize "frmb". For example, you can't call frmb[0].cssClass without first initializing frmb to an array and then adding an object to that array with push(). So, you need to estimate how large you think frmb will be, as well as how large each values sub-array will be.

Related

Matching anagrams and pushing to an array

I have a given word, that I want to match against a given list of words, mainList, and establish which words of that given list are anagrams of the given word, and add them to another list, subList.
I feel like my method to do this is fine, but it returns an unexpected result.
For example...
var word = 'master';
var mainList = ['stream', 'pidgeon', 'maters'];
var subList = [];
Then I take the word, split to an array of letters, alphabetise, and join back into a string. With this string I should be able match against any possible anagrams (which I will covert in the same way).
var mainSorted = [];
for (i = 0; i < word.length; i++) {
mainSorted = word.split('').sort().join();
}
This is where it goes wrong. I loop through the mainList array trying to establish if a given item, when converted, matches the original. If so, I want to push the word to the subList array.
for (var i = 0; i < mainList.length; i++) {
var subSorted = mainList[i].split('').sort().join;
if (mainSorted === subSorted) {
subList.push(mainList[i])
}
}
return subList;
...and the value I expect to see for subList is: ['stream', 'maters']
Yet I am returned an empty array instead.
I've gone through this so many times and I cannot see what's going wrong, would really appreciate some help!
Also, I'm aware there's probably more eloquent methods to do this (and I welcome any suggestions) but primarily I want to see where this is going wrong.
Thanks in advance.
You forgot () at the end of join
var subSorted = mainList[i].split('').sort().join;
should be
var subSorted = mainList[i].split('').sort().join();
One non-issue is
for (i = 0; i < word.length; i++) {
mainSorted = word.split('').sort().join();
}
doesnt need to be in a loop
mainSorted = word.split('').sort().join();
alone suffices
as a bonus, here's a tidier way of doing what you are doing
var word = 'master';
var mainList = ['stream', 'pidgeon', 'maters'];
var mainSorted = word.split('').sort().join();
return mainList.filter(function(sub) {
return sub.split('').sort().join() == mainSorted;
});

How to return a substring between two matching substrings in JavaScript?

I am brand new to programming and just getting started in an online program. The problem I am being presented with is:
Return a substring between two matching substrings.
The string I'm using is:
"Violets are blue, the sky is really blue"
I am trying to produce the substring between the two "blue"s.
That is:
", the sky is really "
This was one of my attempts which doesn't work. I was trying to slice it using indexOf() and lastIndexOf().
module.exports.substringBetweenMatches = function(text, searchString) {
return text.substring(function indexOf(searchString), function lastIndexOf(searchString);
};
module.exports.substringBetweenMatches("Violets are blue, the sky is really blue", "blue");
Any suggestions would be appreciated.
If the string will potentially have more than 2 "matches", you could split the string on the matches, then loop through and concat the strings back together:
var array = text.split(searchString); // split the given text, on the search term/phrase
if (array.length > 2) { // check to see if there were multiple sub-sections made
var string = "";
for (var i = 1; i < array.length; i++) { // start at 1, so we don't take whatever was before the first search term
string += array[i]; // add each piece of the array back into 1 string
}
return string;
}
return array[1];
This is pretty much the idea. I might have messed up the syntax for JavaScript in some places, but the logic is such:
function endsWith(a, s) {
var does_it_match = true;
var start_length = a.length()-s.length()-1;
for (int i=0; i<s.length(); i++) {
if (a[start_length+i]!=s.charAt(i)) {
does_it_match = false;
}
}
return does_it_match;
}
var buffer = new Array();
var return_string = "";
var read = false;
for (int i=0; i<string1.length(); i++) {
buffer.push(string1.charAt(1));
if (endsWith(buffer, "blue") && read==false) {
buffer = new Array();
read = true;
}
else if(endsWith(buffer, "blue") && read==true) {
break;
}
if (read==true) {
return_string = return_string.concat(string1.charAt(i));
}
}
return return_string;
I have stumbled upon this problem myself as a student on the Bloc.io bootcamp program. I stuck to the lessons string.substring() method and also string.indexOf() methods. Here is my go at this answer.
substringBetweenMatches = function(text, searchString) { //where text is your full text string and searchString is the portion you are trying to find.
var beginning = text.indexOf(searchString)+searchString.length; // this is the first searchString index location - the searchString length;
var ending = text.lastIndexOf(searchString); // this is the end index position in the string where searchString is also found.
return(text.substring(beginning,ending)); // the substring method here will cut out the text that doesn't belong based on our beginning and ending values.
};
If you are confused by my code, try:
console.log(beginning);
and
console.log(ending);
to see their values and how they would work with the substring() method.
Here is great reference to the substring() method: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/substring
Here is a JS Fiddle test. I use alert() instead of return. The concept is similar. https://jsfiddle.net/felicedeNigris/7nuhujx6/
I hope that is clear enough with my long comments on the sides?
Hope this helps.

How to use a regexp to replace each item in an array using javascript

I'm a beginner with javascript, and after searching I am still running into an error with this part of my code.
I have an array:
var choices = [ '$5/hr', '$6/hr', '$7/hr', '$10/hr' ];
And I want to use a regular expression to return the array as integers so I can use it for further calculations. I know that replace only works on strings and not an array so I have tried the following:
// Strip other characters and return only integers.
for (var i = 0; i < choices.length; i++) {
choices[i] = choices[i].replace(/[^0-9.]/g, '');
}
EDIT: Apparently the issue is somewhere else in my code. Maybe this needs to be wrapped in another function?
Here is the function that this resides in. This function receives an array as a value and will calculate an average using the array received and the choices array which I cannot convert to integers.
// Choice values
var ul = document.getElementById('Results');
var choices = [];
// Get li element choices
for (var i = 0; i < ul.childNodes.length; i++) {
if (ul.childNodes[i].nodeName == "LI") {
choices.push(ul.childNodes[i]);
}
}
// Strip the last element in array since it is the result container.
choices.splice(-1,1);
// Strip other characters and return only integers.
for (var i = 0; i < choices.length; i++) {
choices[i] = choices[i].replace(/[^0-9.]/g, '');
}
Thanks!
The issue is that you are pushing the nodes in your array, not their text content. Try this instead:
choices.push(ul.childNodes[i].textContent)
or:
choices.push(ul.childNodes[i].childNodes[0].nodeValue)

How to split a URL string with parameters into an array using JavaScript

I'm trying to break up a string like this one:
fname=bill&mname=&lname=jones&addr1=This%20House&...
I want to end up with an array indexed like this
myarray[0][0] = fname
myarray[0][1] = bill
myarray[1][0] = mname
myarray[1][1] =
myarray[2][0] = lname
myarray[2][1] = jones
myarray[3][0] = addr
myarray[3][1] = This House
The url is quite a bit longer than the example. This is what I've tried:
var
fArray = [],
nv = [],
myarray = [];
fArray = fields.split('&');
// split it into fArray[i]['name']="value"
for (i=0; i < fArray.length; i++) {
nv = fArray[i].split('=');
myarray.push(nv[0],nv[1]);
nv.length = 0;
}
The final product is intended to be in 'myarray' and it is, except that I'm getting a one dimensional array instead of a 2 dimensional one.
The next process is intended to search for (for example) 'lname' and returning the index of it, so that if it returned '3' I can then access the actual last name with myarray[3][1].
Does this make sense or am I over complicating things?
Your line myarray.push(nv[0],nv[1]); pushes two elements to the array myarray, not a single cell with two elements as you expect (ref: array.push). What you want is myarray.push( [nv[0],nv[1]] ) (note the brackets), or myarray.push(nv.slice(0, 2)) (ref: array.slice).
To simplify your code, may I suggest using Array.map:
var q = "foo=bar&baz=quux&lorem=ipsum";
// PS. If you're parsing from a-tag nodes, they have a property
// node.search which contains the query string, but note that
// it has a leading ? so you want node.search.substr(1)
var vars = q.split("&").map(function (kv) {
return kv.split("=", 2);
});
For searching, I would suggest using array.filter:
var srchkey = "foo";
var matches = vars.filter(function (v) { return v[0] === srchkey; });
NB. array.filter will always return an array. If you always want just a single value, you could use array.some or a bespoke searching algorithm.
for (var i = 0; i < fArray.length; i++) {
nv = fArray[i].split('=');
myarray.push([nv[0],nv[1]]);
}
nv.length = 0; is not required, since you're setting nv in each iteration of the for loop.
Also, use var i in the for-loop, otherwise, you're using / assigning a global variable i, that's asking for interference.

How to extract values from a string in javascript?

I need some help with extracting values from a cookie using javascript.
The string in a cookie looks something like this:
string = 'id=1||price=500||name=Item name||shipping=0||quantity=2++id=2||price=1500||name=Some other name||shipping=10||quantity=2'
By using string.split() and string.replace() and a some ugly looking code I've somehow managed to get the values i need (price, name, shipping, quantity). But the problem is that sometimes not all of the strings in the cookie are the same. Sometimes the sting in a cookie will look something like this :
string = 'id=c1||color=red||size=XL||price=500||name=Item name||shipping=0||quantity=2++id=c1||price=500||name=Item name||shipping=0||quantity=2'
with some items having color and size as parameters and sometimes only one of those.
Is there some more efficient way to explain to my computer that i want the part of the string after 'price=' to be a variable named 'price' etc.
I hope I'm making sense I've tried to be as precise as I could.
Anyway, thank you for any help
EDIT: I just wanted to say thanks to all the great people of StackOverflow for such wonderfull ideas. Because of all of your great suggestions I'm going out to get drunk tonight. Thank you all :)
Let's write a parser!
function parse(input)
{
function parseSingle(input)
{
var parts = input.split('||'),
part,
record = {};
for (var i=0; i<parts.length; i++)
{
part = parts[i].split('=');
record[part[0]] = part[1];
}
return record;
}
var parts = input.split('++'),
records = [];
for (var i=0; i<parts.length; i++)
{
records.push(parseSingle(parts[i]));
}
return records;
}
Usage:
var string = 'id=1||price=500||name=Item name||shipping=0||quantity=2++id=2||price=1500||name=Some other name||shipping=10||quantity=2';
var parsed = parse(string);
/* parsed is:
[{id: "1", price: "500", name: "Item name", shipping: "0", quantity: "2"},
{id: "2", price: "1500", name: "Some other name", shipping: "10", quantity: "2"}]
*/
You can achieve this using regular expressions. For example, the regex /price=([0-9]+)/ will match price=XXX where XXX is one or more numbers. As this part of the regex is surrounded by parenthesis it explicitly captures the numeric part for you.
var string = 'id=1||price=500||name=Item name||shipping=0||quantity=2++id=2||price=1500||name=Some other name||shipping=10||quantity=2'
var priceRegex = /price=([0-9]+)/
var match = string.match(priceRegex);
console.log(match[1]); // writes 500 to the console log
Try that:
var string = 'id=1||price=500||name=Item name||shipping=0||quantity=2++id=2||price=1500||name=Some other name||shipping=10||quantity=2';
var obj = new Array();
var arr = string.split('||');
for(var x=0; x<arr.length;x++){
var temp = arr[x].split('=');
obj[temp[0]] = temp[1]
}
alert(obj['id']); // alert 1
First, split your string into two (or more) parts by ++ separator:
var strings = myString.split('++');
then for each of the strings you want an object, right? So you need to have an array and fill it like that:
var objects = [];
for (var i = 0; i < strings.length; ++i) {
var properties = strings[i].split('||');
var obj = {};
for (var j = 0; j < properties.length; ++j) {
var prop = properties[j].split('=');
obj[prop[0]] = prop[1]; //here you add property to your object, no matter what its name is
}
objects.push(obj);
}
thus you have an array of all objects constructed from your string. Naturally, in real life I'd add some checks that strings indeed satisfy the format etc. But the idea is clear, I hope.
If you can replace the || with &, you could try to parse it as if it were a query string.
A personal note - JSON-formatted data would've been easier to work with.
I would attach the data to a javascript object.
var settingsObj = {};
var components = thatString.split('||');
for(var j = 0; j < components.length; j++)
{
var keyValue = components[j].split('=');
settingsObj[keyValue[0]] = keyValue[1];
}
// Now the key value pairs have been set, you can simply request them
var id = settingsObj.id; // 1 or c1
var name = settingsObj.name; // Item Name, etc
You're already using .split() to break down the string by || just take that a step further and split each of those sections by = and assign everything on the left the field and the right the value
This should get the first match in the string:
string.match(/price=(\d{1,})/)[1]
Note this will only match the first price= in the string, not the second one.
If you can use jQuery, it wraps working with cookies and lets you access them like:
Reading a cookie:
var comments = $.cookie('comments');
Writing a cookie:
$.cookie('comments', 'expanded');
This post by someone else has a decent example:
http://www.vagrantradio.com/2009/10/getting-and-setting-cookies-with-jquery.html
If you can't use jQuery, you need to do standard string parsing like you currently are (perhaps regular expressions instead of the string splitting / replacing might trim down your code) or find some other javascript library that you can use.
If you like eye candies in your code you can use a regexp based "search and don't replace" trick by John Resig (cached here) :
var extract = function(string) {
var o = {};
string.replace(/(.*?)=(.*?)(?:\|\||$)/g, function(all, key, value) {
o[key] = value;
});
return o;
};
Then
var objects = string.split('++'),
i = objects.length;
for (;i--;) {
objects[i] = extract(objects[i]);
}
You could do something like this, where you eval the strings when you split them.
<html>
<head>
<script type="text/javascript">
var string = 'id=c1||color=red||size=XL||price=500||name=Item name||shipping=0||quantity=2++id=c1||price=500||name=Item name||shipping=0||quantity=2'
var mySplitResult = string.split("||");
for(i = 0; i < mySplitResult.length; i++){
document.write("<br /> Element " + i + " = " + mySplitResult[i]);
var assignment = mySplitResult[i].split("=");
eval(assignment[0] + "=" + "\""+assignment[1]+"\"");
}
document.write("Price : " + price);
</script>
</head>
<body>
</body>
</html>
var str = 'id=c1||color=red||size=XL||price=500||name=Item name||shipping=0||quantity=2++id=c1||price=500||name=Item name||shipping=0||quantity=2'
var items = str.split("++");
for (var i=0; i<items.length; i++) {
var data = items[i].split("||");
for (var j=0; j<data.length; j++) {
var stuff = data[j].split("=");
var n = stuff[0];
var v = stuff[1];
eval("var "+n+"='"+v+"'");
}
alert(id);
}
EDIT: As per JamieC's suggestion, you can eliminate eval("var "+n+"='"+v+"'"); and replace it with the (somewhat) safer window[n] = v; -- but you still have the simple problem that this will overwrite existing variables, not to mention you can't tell if the variable color was set on this iteration or if this one skipped it and the last one set it. Creating an empty object before the loop and populating it inside the loop (like every other answer suggests) is a better approach in almost every way.
JSON.parse('[{' + string.replace(/\+\+/g, '},{').replace(/(\w*)=([\w\s]*)/g, '"$1":"$2"').replace(/\|\|/g, ',') + '}]')
Convert the string for JSON format, then parse it.

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