I have a cookie that stores 5 values separated by commas in one cookie. I'm able to retrieve the value of ExampleCookie as follows (as example):
var CookieValue = readCookie('ExampleCookie');
//returns Foo,Bar,Foo1,FooFighter,Bar2
How do I parse through CookieValue to assign individual variables such that I can assign a variable to each of the 5 parts?
I've found ways to do this with PHP but not javascript.
Thanks in advance for any advice.
use the String.split(delimiter) method
var array = readCookie('ExCook').split(",");
Reference:
https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/split
You need to make an array from string:
CookieParams = CookieValue.split(",");
CookieParams[0] = Foo
CookieParams[1] = Bar
You could split the CookieValue into individual values in an array via the the split() method.
var valList = CookieValue.split(','); // ["Foo", "Bar", "Foo1", "FooFighter", "Bar2"]
If you then want the values to be assigned to individual variables, you would need to loop through the array and manually make the assignment.
JSON.stringify, and JSON.parse are your best cleanest bets (imho)
var values = JSON.parse(readCookie('ExampleCookie'));
createCookie('ExampleCookie',JSON.stringify(values));
This has the added benefit of being able to set key values in your object/array.
Assuming you're using the functions found at quirks mode just ensure your cookie values stringified don't go over the 4000 char limit found in most browsers.
I quickly realized this was more of a question on Split than about cookies. Here is what i came up w/.
var splits = ExampleCookie.split(",");
var slot1 = splits[0];
var slot2 = splits[1];
var slot3 = splits[2]; etc.
Related
I store a lot of values in localStorage for an app and needed a way of converting the "string" back into a number - IF it was a number. The thought being if you force HTML <input type="number"> on your form, then the data going into the form and extracted from the form IS a number, but once stored - its converted to a string. So to repopulate that field later, you must read the localStorage value and convert it back to a number before repopulating the input field - otherwise you start getting a lot of reptitive warnings and sometimes errors because NUMBERS are expected, but localStorage is retrieving strings.
My method: Assuming the value is inputted as a number, then only a number (digits only) will be stored - thus you can assume only numbers will come out (even if they are a string). Knowing only numbers will come back allows for this:
var allVariables = {} ;
var reg = new RegExp(/^\d+$/) ; // this accounts for digits only
for (var x=0; x<localStorage.length;x++) {
var keyValue = localStorage.getItem(localStorage.key(x)) ;
if (reg.text(keyValue)) {
keyValue = parseInt(keyValue) ;
}
allVariables[localStorage.key(x)] = keyValue ;
}
I even expanded on this to account for true/false booleans...can't use 0/1 easily without get confused with a number. Another method I have seen is underscoring the key name to identify the typeof for later conversion:
ie:
key1_str
key2_boo
key3_int
key4_obj
key5_flo
Then identify the "_xxx" to convert that value appropriately.
I am asking to see others approach to this problem or suggestions and recommendations on how to improve it. Mine is not perfect...though neither is localStorage...but still looking for improvement.s
suppose you have "keyName" : "12345".
Tricky solution is var newInt = +localStorage.getItem('keyName')
this extra + will convert the string to integer.
Instead of storing lots of single keys you might consider storing whole objects to less numbers of storage keys that you stringfiy to json and parse when retrieving. JSON methods will retain type
var obj= {
id:100,
anotherProp:'foo'
}
localStorage.setItem('myObj',JSON.stringify(obj));
var newObj = JSON.parse(localStorage.getItem('myObj'));
console.log(typeof newObj.id)//number
try to convert:
function getProbablyNumberFromLocalStorage(key) {
var val = localStorage.getItem(key);
return (isNan(+val) || val==null) ? val : +val;
}
I have an array that comes in from from my API that I would like to arrange in a way that is better for the user (namely, in a column as opposed to the typical comma separated printed array).
This is my JS Fiddle to give a clearer picture: https://jsfiddle.net/2z89owas/
My question is, how can I get output3 to display just like output (and maintain its status as an iterable array like it was as dates)?
First you should not be using value for an html element. You can use .value for extracting value from inputs. Change your line to:
var val = document.getElementById('output2').innerHTML;
Afterwards, you have to split the same way you did join.
var dates3 = val.split('<br>');
document.getElementById('output3').innerHTML = dates3;
You can directly use join, something like:
document.getElementById('output3').innerHTML = dates.join(',');
You can try mapping over the contents of dates instead, as so:
let datesElem = dates.map(date =>`<p>${date}</p>`);
// test: console.log(datesElem)
document.getElementById('output3').innerHTML = datesElem
I am using IBM BPM 8.6
I have an input string as follows:
"\"RECORD_CONTACT\":\"Maram\" , \"DRUG\":\"Panadol\"
In a script on server side, I want to dynamically create a business object like this:
tw.local.recordContact = Maram;
tw.local.drug = Panadol;
How can I dynamically create the business object?
There are a few problems with your request. The first is that you are not creating a business object, you are creating variables. In IBM BPM the variables have to be declared at design time or you will get an error, so invoking attempting to call something like -
tw.local.myVariable = 'Bob';
Will throw an exception if tw.local.myVariable has not been declared. Base on your other question you asked here (link), I'm going to assume you actually have an ANY variable declared called "return" so that
tw.local.return.myVariable = 'Bob'
will work. Given that I based on Sven's answer I think something like the following will work (you will need to validate)
var str = "\"RECORD_CONTACT\":\"Maram\" , \"DRUG\":\"Panadol\"";
var jsonStr = "{" + str.replace(/\\\"/g,'\"') + "}";
var tempValue = JSON.parse(jsonStr);
var keyArray = Object.keys(tempValue);
var valueArray = Object.values(tempValue);
for(var keyCount=0; keyCount<keyArray.length; keyCount++{
var evalString = "tw.local.return."+keyArray[keyCount]+"="+valueArray[keyCount];
eval(evalString);
}
I'll note that doing this is a very bad idea as it would be very brittle code and that using eval() in this manner opens you up to all sorts of possible exploits. It will also fail badly if the value for one of the keys is not a simple type.
-Andrew Paier
One should know what you are going to do with dynamically created Business Objects (BO) to answer you better. Like a very generic way would be - creating JSON object instead of BO.
But if you want to stick with BO then this is only possible when you know all the BO structure (schema) beforehand during design time.
var str = "\"RECORD_CONTACT\":\"Maram\" , \"DRUG\":\"Panadol\"";
vat objArray = str.split("reg ex to split each object string")
foreach (obj in objArray ){
if(obj.indexOf( "RECORD_CONTACT")!=-1)
tw.local.recordContact = new tw.object.RECORD_CONTACT();
//below goes code get value of each attribute of BPM from string
}
else if(obj.indexOf( "DRUG")!=-1){
//similar code to create BO DRUG
}
Don't forget to create BO before using those :)
I have this code:
var string = '{"items":[{"Desc":"Item1"},{"Desc":"Item2"}]}';
localStorage.setItem('added-items', JSON.stringify(string));
This code will use localStorage.
Here is now the code to get the stored data:
var retrievedObject = localStorage.getItem('added-items');
My problem now is, how can i get the size of the data items? answer must be 2.
How can i get the "Item1" and "Item2"?
I tried retrievedObject[0][0] but it is not working.
And how to add data on it?
so it will be
{"items":[{"Desc":"Item1"},{"Desc":"Item2"},{"Desc":"Item3"}]}
Can I use JSON.stringify?
var string = '{"items":[{"Desc":"Item1"},{"Desc":"Item2"}]}';
localStorage.setItem('added-items', JSON.stringify(string));
stringify means, take an object and return its presentation as a string.
What you have, is already a string and not a JSON object.
The opposite is JSON.parse which takes a string and turns it into an object.
Neither of them have anything to do with getting the size of an array. When properly coding JavaScript you almost never use JSON.parse or JSON.stringify. Only if serialization is explicitly wanted.
Use length for the size of the array:
var obj = {"items":[{"Desc":"Item1"},{"Desc":"Item2"},{"Desc":"Item3"}]}
console.debug(obj.items.length);
// THIS IS ALREADY STRINGIFIED
var string = '{"items":[{"Desc":"Item1"},{"Desc":"Item2"}]}';
// DO NOT STRINGIFY AGAIN WHEN WRITING TO LOCAL STORAGE
localStorage.setItem('added-items', string);
// READ STRING FROM LOCAL STORAGE
var retrievedObject = localStorage.getItem('added-items');
// CONVERT STRING TO REGULAR JS OBJECT
var parsedObject = JSON.parse(retrievedObject);
// ACCESS DATA
console.log(parsedObject.items[0].Desc);
To bring clarity to future people that may stumble across this question and found the accepted answer to not be everything you hoped and dreamed for:
I've extended the question so that the user may either want to input a string or JSON into localStorage.
Included are two functions, AddToLocalStorage(data) and GetFromLocalStorage(key).
With AddToLocalStorage(data), if your input is not a string (such as JSON), then it will be converted into one.
GetFromLocalStorage(key) retrieves the data from localStorage of said key
The end of the script shows an example of how to examine and alter the data within JSON. Because it is a combination of objects and array, one must use a combination of . and [] where they are applicable.
var string = '{"items":[{"Desc":"Item1"},{"Desc":"Item2"}]}';
var json = {"items":[{"Desc":"Item1"},{"Desc":"Item2"},{"firstName":"John"},{"lastName":"Smith"}]};
localStorage.setItem('added-items', AddToLocalStorage(string));
localStorage.setItem('added-items', AddToLocalStorage(json));
// this function converts JSON into string to be entered into localStorage
function AddToLocalStorage(data) {
if (typeof data != "string") {data = JSON.stringify(data);}
return data;
}
// this function gets string from localStorage and converts it into JSON
function GetFromLocalStorage(key) {
return JSON.parse(localStorage.getItem(key));
}
var myData = GetFromLocalStorage("added-items");
console.log(myData.items[2].firstName) // "John"
myData.items[2].firstName = ["John","Elizabeth"];
myData.items[2].lastName = ["Smith","Howard"];
console.log(myData.items[2]) // {"firstName":["John","Elizabeth"],"lastName":["Smith","Howard"]}
console.log(myData.items.length) // 4
JSON.parse is definitely the best way to create an object but I just want to add if that doesn't work (because of lack of support), obj = eval('(' + str + ')'); should work. I've had a problem with a HTML to PDF converter in the past that didn't include JSON.parse and eval did the trick. Try JSON.parse first.
Access your object: obj.items[0].Desc;
var object = Json.parse(retrievedObject);
Now you can access it just like an array
https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse
If you need more help i have some previous code where i am reading Json from local storage and making a form from that json. This code will help in understanding how to traverse that array
Json stored in localstorage
{"form":[{"element":"input", "type":"text","name":"name","value":"value","min":"2","max":"10"}]}
JavaScript to read that json
function readJson(){
if(!form_created){
add_form();
}
var fetched_json = localStorage.getItem("json");
var obj=JSON.parse(fetched_json);
for(var i=0; i<obj.form.length;i++){
var input = document.createElement(obj.form[i].element);
input.name = obj.form[i].name;
input.value = obj.form[i].value;
input.type = obj.form[i].type;
input.dataset.min = obj.form[i].min;
input.dataset.max = obj.form[i].max;
input.dataset.optional = obj.form[i].optional;
form.insertBefore (input,form.lastChild);
}
alert(obj.form[0].name);
}
I have a group of strings in Javascript and I need to write a function that detects if another specific string belongs to this group or not.
What is the fastest way to achieve this? Is it alright to put the group of values into an array, and then write a function that searches through the array?
I think if I keep the values sorted and do a binary search, it should work fast enough. Or is there some other smart way of doing this, which can work faster?
Use a hash table, and do this:
// Initialise the set
mySet = {};
// Add to the set
mySet["some string value"] = true;
...
// Test if a value is in the set:
if (testValue in mySet) {
alert(testValue + " is in the set");
} else {
alert(testValue + " is not in the set");
}
You can use an object like so:
// prepare a mock-up object
setOfValues = {};
for (var i = 0; i < 100; i++)
setOfValues["example value " + i] = true;
// check for existence
if (setOfValues["example value 99"]); // true
if (setOfValues["example value 101"]); // undefined, essentially: false
This takes advantage of the fact that objects are implemented as associative arrays. How fast that is depends on your data and the JavaScript engine implementation, but you can do some performance testing easily to compare against other variants of doing it.
If a value can occur more than once in your set and the "how often" is important to you, you can also use an incrementing number in place of the boolean I used for my example.
A comment to the above mentioned hash solutions.
Actually the {} creates an object (also mentioned above) which can lead to some side-effects.
One of them is that your "hash" is already pre-populated with the default object methods.
So "toString" in setOfValues will be true (at least in Firefox).
You can prepend another character e.g. "." to your strings to work around this problem or use the Hash object provided by the "prototype" library.
Stumbled across this and realized the answers are out of date. In this day and age, you should not be implementing sets using hashtables except in corner cases. You should use sets.
For example:
> let set = new Set();
> set.add('red')
> set.has('red')
true
> set.delete('red')
true
> set.has('red')
false
Refer to this SO post for more examples and discussion: Ways to create a Set in JavaScript?
A possible way, particularly efficient if the set is immutable, but is still usable with a variable set:
var haystack = "monday tuesday wednesday thursday friday saturday sunday";
var needle = "Friday";
if (haystack.indexOf(needle.toLowerCase()) >= 0) alert("Found!");
Of course, you might need to change the separator depending on the strings you have to put there...
A more robust variant can include bounds to ensure neither "day wed" nor "day" can match positively:
var haystack = "!monday!tuesday!wednesday!thursday!friday!saturday!sunday!";
var needle = "Friday";
if (haystack.indexOf('!' + needle.toLowerCase() + '!') >= 0) alert("Found!");
Might be not needed if the input is sure (eg. out of database, etc.).
I used that in a Greasemonkey script, with the advantage of using the haystack directly out of GM's storage.
Using a hash table might be a quicker option.
Whatever option you go for its definitely worth testing out its performance against the alternatives you consider.
Depends on how much values there are.
If there are a few values (less than 10 to 50), searching through the array may be ok. A hash table might be overkill.
If you have lots of values, a hash table is the best option. It requires less work than sorting the values and doing a binary search.
I know it is an old post. But to detect if a value is in a set of values we can manipulate through array indexOf() which searches and detects the present of the value
var myString="this is my large string set";
var myStr=myString.split(' ');
console.log('myStr contains "my" = '+ (myStr.indexOf('my')>=0));
console.log('myStr contains "your" = '+ (myStr.indexOf('your')>=0));
console.log('integer example : [1, 2, 5, 3] contains 5 = '+ ([1, 2, 5, 3].indexOf(5)>=0));
You can use ES6 includes.
var string = "The quick brown fox jumps over the lazy dog.",
substring = "lazy dog";
console.log(string.includes(substring));