Why is JavaScript's split() method not splitting on ":"? - javascript

So to start off, a bit of context. I am pulling data from the following url: "https://webster.cs.washington.edu/pokedex/pokedex.php?pokedex=all" using a GET method. The data returned is a series of Pokemon names and image names in the following format.
Name1:name1.png
Name2:name2.png
...
The list is 151 items long. When I call the typeOf() method "String" is returned, so I am fairly certain it is a String I am dealing with here. What I would like to do is split the String on the delimiters of "\n" and ":".
What I would like:
Name1,name1.png,Name2,name2.png...
After some experimentation with Regex, I found that the Regex to do this was "\n|:". Using this I wrote the following line to split the String apart. I tested this Regex on https://regex101.com and it seems to work properly there.
var splitData = data.split("\n|:");
("data" is the String I receive from the url.)
But instead of splitting the String and placing the substrings into an array it doesn't do anything. (At least as far as I can see.) As such my next idea was to try replacing the characters that were giving me trouble with another character and then splitting on that new character.
data = data.replace("\n", " ");
data = data.replace("/:/g", " ");
var splitData = data.split(" ");
The first line that replaces new line characters does work, but the second line to replace the ":" does not seem to do anything. So I end up with an array that is filled with Strings that look like this.
Name1:name1.png
I can split these strings by calling their index and then splitting the substring stored within, which only confuses me more.
data = data.replace("\n", " ");
var splitData = data.split(" ");
alert(splitData[0].split(":")[1]);
The above code returns "name1.png".
Am I missing something regarding the split() method? Is my Regex wrong? Is there a better way to achieve what I am attempting to do?


Right now you are splitting on the string literal "\n|:" but to do a regex you want data.split(/[:\n]/)
The MDN page shows two ways to build a Regex:
var regex1 = /\w+/;
var regex2 = new RegExp('\\w+');


The following test script was able to work for me. I decided to use the regex in the split instead of trying to replace tokens in the string. It seemed to do the trick for me.
let testResponse = `Abra:abra.png
Aerodactyl:aerodactyl.png`;
let dataArray = testResponse.split(/\n|:/g);
let commaSeperated = dataArray.join(',');
console.log(commaSeperated);


So you can simply use regex by excluding the quotes all together.
You can look at the documentation here for regular expressions. They give the following examples:
var re = /ab+c/;
var re = new RegExp('ab+c');
See below for your expected output:
var data = `Name1:name1.png
Name2:name2.png`;
var splitData = data.split(/[\n:]/);
console.log(splitData);
//Join them by a comma to get all results
console.log(splitData.join(','));
//For some nice key value pairs, you can reduce the array into an object:
var kvps = data.split("\n").reduce((res, line) => {
var split = line.split(':');
return {
...res,
[split[0]]: split[1]
};
}, {});
console.log(kvps);


I tried and this works good.
str.split(/[:\n]/)
Here is a plunker.
plunker

Related

How to remove strings before nth character in a text?

I have a dynamically generated text like this
xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0
How can I remove everything before Map ...? I know there is a hard coded way to do this by using substring() but as I said these strings are dynamic and before Map .. can change so I need to do this dynamically by removing everything before 4th index of - character.

You could remove all four minuses and the characters between from start of the string.
var string = 'xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0',
stripped = string.replace(/^([^-]*-){4}/, '');
console.log(stripped);

I would just find the index of Map and use it to slice the string:
let str = "xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0"
let ind = str.indexOf("Map")
console.log(str.slice(ind))
If you prefer a regex (or you may have occurrences of Map in the prefix) you man match exactly what you want with:
let str = "xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0"
let arr = str.match(/^(?:.+?-){4}(.*)/)
console.log(arr[1])

I would just split on the word Map and take the first index
var splitUp = 'xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0'.split('Map')
var firstPart = splitUp[0]

Uses String.replace with regex expression should be the popular solution.
Based on the OP states: so I need to do this dynamically by removing everything before 4th index of - character.,
I think another solution is split('-') first, then join the strings after 4th -.
let test = 'xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0'
console.log(test.split('-').slice(4).join('-'))

javascript split string function not working

I am trying to split a string:
var str = "*HQ,6170930129,V1,185409,A,3132.3228,N,07424.7726,E,000.04,000,280618,FBFFBBFF,410,04,08028,40555#*HQ,6170930129,V1,185413,A,3132.3226,N,07424.7735,E,000.15,000,280618,FBFFBBFF,410,04,08028,40555"
var res = device_data.split('*');
But it's not working. it's just displaying this string
var str = "*HQ,6170930129,V1,185409,A,3132.3228,N,07424.7726,E,000.04,000,280618,FBFFBBFF,410,04,08028,40555#*HQ,6170930129,V1,185413,A,3132.3226,N,07424.7735,E,000.15,000,280618,FBFFBBFF,410,04,08028,40555"
var res = str.split('*');
console.dir(res)
,HQ,6170930129,V1,185409,A,3132.3228,N,07424.7726,E,000.04,000,280618,FBFFBBFF,410,04,08028,40555#,HQ,6170930129,V1,185413,A,3132.3226,N,07424.7735,E,000.15,000,280618,FBFFBBFF,410,04,08028,40555
Instead of creating an array with two elements.

IMHO, you want something like this:
var str = "*HQ,6170930129,V1,185409,A,3132.3228,N,07424.7726,E,000.04,000,280618,FBFFBBFF,410,04,08028,40555#*HQ,6170930129,V1,185413,A,3132.3226,N,07424.7735,E,000.15,000,280618,FBFFBBFF,410,04,08028,40555"
splitStrArr = str.split('*').filter(str => str != "")
console.log(splitStrArr)
console.log(splitStrArr[0])
console.log(splitStrArr[1])

You are getting a string with a period in the beginning because whatever you are doing leads to the result of String#split being converted to a string. String#split returns an array. An array converted to a string is of the form of element0,element1,element2 ... elements separated by commas.
The result of String#split in your case is ["",...] with 3 elements since your string begins with the character '*' you are searching, so String#split will create an empty string as the first element of the returned array. So the result is exactly as expected, and String#split is working as intended.
get rid of the first character of the string,
mystring.substr(1).split('*')
get rid of the empty strings
mystring.split('*').filter(s=>s!='')
to obtain the desired result.

You can use:
var res = str.split("#");
You can check in Javascript console in browser itself.
As a suggestion/ idea, you can always use the browser console, for example, Chrome browser, to execute simple scripts like these.
This way, you can save time, as it is easier to check your data structures, their internal data.

If you try
var res = str.split('*');
you obtain three elements:
res[0] is '' (empty string)
res[1] is 'HQ,61...'
res[2] is 'HQ,...'

Extract Twitter handlers from string using regex in JavaScript

I Would like to extract the Twitter handler names from a text string, using a regex. I believe I am almost there, except for the ">" that I am including in my output. How can I change my regex to be better, and drop the ">" from my output?
Here is an example of a text string value:
"PlaymakersZA, Absa, DiepslootMTB"
The desired output would be an array consisting of the following:
PlaymakersZA, Absa, DiepslootMTB
Here is an example of my regex:
var array = str.match(/>[a-z-_]+/ig)
Thank you!

You can use match groups in your regex to indicate the part you wish to extract.
I set up this JSFiddle to demonstrate.
Basically, you surround the part of the regex that you want to extract in parenthesis: />([a-z-_]+)/ig, save it as an object, and execute .exec() as long as there are still values. Using index 1 from the resulting array, you can find the first match group's result. Index 0 is the whole regex, and next indices would be subsequent match groups, if available.
var str = "PlaymakersZA, Absa, DiepslootMTB";
var regex = />([a-z-_]+)/ig
var array = regex.exec(str);
while (array != null) {
alert(array[1]);
array = regex.exec(str);
}

You could just strip all the HTML
var str = "PlaymakersZA, Absa, DiepslootMTB";
$handlers = str.replace(/<[^>]*>|\s/g,'').split(",");

How do I get a list of strings ending in a newline or ending in the end of the string in javascript regex?

I'm pretty frustrated with regex right now. Given:
var text = "This is a sentence.\nThis is another sentence\n\nThis is the last sentence!"
I want regex to return to me:
{"This is a sentence.\n", "This is another sentence\n\n", "This is the last sentence!"}
I think i should use
var matches = text.match(/.+[\n+\Z]/)
but \Z doesn't seem to work. Does javascript have an end of string matcher?

You can use the following regex.
var matches = text.match(/.+\n*/g);
Working Demo
Or you could match a newline sequence "one or more" times or the end of the string.
var matches = text.match(/.+(?:\n+|$)/g);

Try this one: /(.+\n*)/g
See it here: http://regex101.com/r/wK8oX3/1

If you wanted an array and didn't want to keep the "\n" around you could do...
var strings = text.split("\n");
which would yield
["This is a sentence.", "This is another sentence", "", "This is the last sentence!"]
if you wanted to get rid of that empty string chain a filter onto the split...
var strings = text.split("\n").filter(function(s){ return s !== ""; });
Maybe not what you want tho, also not as efficient as the regex options already proposed.
Edit: as torazaburo pointed out using Boolean as the filter function is cleaner than a callback.
var strings = text.split("\n").filter(Boolean);
Edit Again: I keep getting one upped, using the /\n+/ expression is even cooler.
var strings = text.split(/\n+/);

To get an array of sentences:
var matches = text.match(/.+?(?:(?:\\n)+|$)/g);

You can try this,
text.match(/.+/g)

Splitting string in javascript

How can I split the following string?
var str = "test":"abc","test1":"hello,hi","test2":"hello,hi,there";
If I use str.split(",") then I won't be able to get strings which contain commas.
Whats the best way to split the above string?

I assume it's actually:
var str = '"test":"abc","test1":"hello,hi","test2":"hello,hi,there"';
because otherwise it wouldn't even be valid JavaScript.
If I had a string like this I would parse it as an incomplete JSON which it seems to be:
var obj = JSON.parse('{'+str+'}');
and then use is as a plain object:
alert(obj.test1); // says: hello,hi
See DEMO
Update 1: Looking at other answers I wonder whether it's only me who sees it as invalid JavaScript?
Update 2: Also, is it only me who sees it as a JSON without curly braces?

Though not clear with your input. Here is what I can suggest.
str.split('","');
and then append the double quotes to each string

str.split('","'); Difficult to say given the formatting
if Zed is right though you can do this (assuming the opening and closing {)
str = eval(str);
var test = str.test; // Returns abc
var test1 = str.test1; // returns hello,hi
//etc

That's a general problem in all languages: if the items you need contain the delimiter, it gets complicated.
The simplest way would be to make sure the delimiter is unique. If you can't do that, you will probably have to iterate over the quoted Strings manually, something like this:
var arr = [];
var result = text.match(/"([^"]*"/g);
for (i in result) {
arr.push(i);
}

Iterate once over the string and replace commas(,) following a (") and followed by a (") with a (%) or something not likely to find in your little strings. Then split by (%) or whatever you chose.

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