Manipulating occurrences of all letters in a string in Javascript - javascript

Desired functionality:
var myString = "123a4 1b234";
console.log(myString.allInstancesOfLetter().something();
//"123A4 1B234"
Is there a way to do this without having to complicate things with an array of all 26 letters etc.?
edit: toUpperCase() causing confusion, I didn't really think of that interaction, I was just choosing a random function.

You can set a callback function as second parameter when using the replace method that will be applied to each ocurrence in a set RegExp.
const myString = "123a4 1b234";
const result = myString.replace(/[a-z]/g, function(char) {
return char.toUpperCase();
});
console.log(result);

toUpperCase isnt applied to numbers, so
"123a4 1b234".toUpperCase()
works as expected.

You just need String.prototype.toUpperCase()
var myString = "123a4 1b234";
console.log(myString.toUpperCase());

Related

Javascript regex parse complex url string

I need to parse a complex URL string to fetch specific values.
From the following URL string:
/api/rss/feeds?url=http://any-feed-url-a.com?filter=hot&format=rss&url=http://any-feed-url-b.com?filter=rising&format=rss
I need to extract this result in array format:
['http://any-feed-url-a.com?filter=hot&format=rss', 'http://any-feed-url-b.com?filter=rising&format=rss']
I tried already with this one /url=([^&]+)/ but I can't capture all correctly all the query parameters. And I would like to omit the url=.
RegExr link
Thanks in advance.
This regex works for me: url=([a-z:/.?=-]+&[a-z=]+)
also, you can test this: /http(s)?://([a-z-.?=&])+&/g
const string = '/api/rss/feeds?url=http://any-feed-url.com?filter=hot&format=rss&url=http://any-feed-url.com?filter=latest&format=rss'
const string2 = '/api/rss/feeds?url=http://any-feed-url.com?filter=hot&format=rss&next=parm&url=http://any-feed-url.com?filter=latest&format=rss'
const regex = /url=([a-z:/.?=-]+&[a-z=]+)/g;
const regex2 = /http(s)?:\/\/([a-z-.?=&])+&/g;
console.log(string.match(regex))
console.log(string2.match(regex2))
have you tried to use split method ? instead of using regex.
const urlsArr = "/api/rss/feeds?url=http://any-feed-url-a.com?filter=hot&format=rss&url=http://any-feed-url-b.com?filter=rising&format=rss".split("url=");
urlsArr.shift(); // removing first item from array -> "/api/rss/feeds?"
console.log(urlsArr)
)
which is going to return ["/api/rss/feeds?", "http://any-feed-url-a.com?filter=hot&format=rss&", "http://any-feed-url-b.com?filter=rising&format=rss"] then i am dropping first item in array
if possible its better to use something else then regex CoddingHorror: regular-expressions-now-you-have-two-problems
You can matchAll the url's, then map the capture group 1 to an array.
str = '/api/rss/feeds?url=http://any-feed-url-a.com?filter=hot&format=rss&url=http://any-feed-url-b.com?filter=rising&format=rss'
arr = [...str.matchAll(/url=(.*?)(?=&url=|$)/g)].map(x => x[1])
console.log(arr)
But matchAll isn't supported by older browsers.
But looping an exec to fill an array works also.
str = '/api/rss/feeds?url=http://any-feed-url-a.com?filter=hot&format=rss&url=http://any-feed-url-b.com?filter=rising&format=rss'
re = /url=(.*?)(?=&url=|$)/g;
arr = [];
while (m = re.exec(str)) {
arr.push(m[1]);
}
console.log(arr)
If your input is better-formed in reality than shown in the question and you’re targeting a modern JavaScript environment, there’s URL/URLSearchParams:
const input = '/api/rss/feeds?url=http://any-feed-url-a.com?filter=hot%26format=rss&url=http://any-feed-url-b.com?filter=rising%26format=rss';
const url = new URL(input, 'http://example.com/');
console.log(url.searchParams.getAll('url'));
Notice how & has to be escaped as %26 for it to make sense.
Without this input in a standard form, it’s not clear which rules of URLs are still on the table.

Dynamic string cutting

Okay, so I have a filepath with a variable prefix...
C:\Users\susan ivey\Documents\VKS Projects\secc-electron\src\views\main.jade
... now this path will be different for whatever computer I'm working on...
is there a way to traverse the string up to say 'secc-electron\', and drop it and everything before it while preserving the rest of it? I'm familiar with converting strings to arrays to manipulate elements contained within delimiters, but this is a problem that I have yet to come up with an answer to... would there be some sort of regex solution instead? I'm not that great with regex so I wouldn't know where to begin...
What you probably want is to do a split (with regex or not):
Here's an example:
var paragraph = 'C:\\Users\\susan ivey\\Documents\\VKS Projects\\secc-electron\\src\\views\\main.jade';
var splittedString = paragraph.split("secc-electron"); // returns an array of 2 element containing "C:\\Users\\susan ivey\\Documents\\VKS Projects\\" as the first element and "\\src\\views\\main.jade" as the 2nd element
console.log(splittedString[1]);
You can have a look at this https://www.w3schools.com/jsref/jsref_split.asp to learn more about this function.
With Regex you can do:
var myPath = 'C:\Users\susan ivey\Documents\VKS Projects\secc-electron\src\views\main.jade'
var relativePath = myPath.replace(/.*(?=secc-electron)/, '');
The Regex is:
.*(?=secc-electron)
It matches any characters up to 'secc-electron'. When calling replace it will return the last part of the path.
You can split the string at a certain point, then return the second part of the resulting array:
var string = "C:\Users\susan ivey\Documents\VKS Projects\secc-electron\src\views\main.jade"
console.log('string is: ', string)
var newArray = string.split("secc-electron")
console.log('newArray is: ', newArray)
console.log('newArray[1] is: ', newArray[1])
Alternatively you could use path.parse(path); https://nodejs.org/api/path.html#path_path_parse_path and retrieve the parts that you are interested in from the object that gets returned.

Javascript: given an array of variables, function to remove characters and output another array

so I am still learning Javascript, so I know this is a basic questions, and I'd really like to learn what I'm missing. I have an array of variables, and I need a function that removes special characters, and returns the result as an array.
Here's my code:
var myArray = [what_hap, desc_injury];
function ds (string) {
string.replace(/[\\]/g, ' ')
string.replace(/[\"]/g, ' ')
string.replace(/[\/]/g, '-')
string.replace(/[\b]/g, ' ')
string.replace(/[\f]/g, ' ')
string.replace(/[\n]/g, ',')
string.replace(/[\r]/g, ' ')
string.replace(/[\t]/g, ' ');
return string;
}
ds (myArray);
I know that's not going to work, so I'm just trying to learn the simplest and cleanest way to output:
[whatHap: TEXTw/oSpecialCharacters, descInj: TEXTw/oSpecialCharacters]
Anyone willing to guide a noobie? Thanks! :)
The comments on the question are correct, you need to specify what you are asking a little better but I will try and give you some guidance from what I assume about your intended result.
One important thing to note which would fix the function you already have is that string.replace() will not change the string itself, it returns a new string with the replacements as you can see in the documentation. to do many replacements you need to do string = string.replace('a', '-')
On to a solution for the whole array. There are a couple ways to process an array in javascript: for loop, Array.forEach(), or Array.map(). I urge you to read the documentation of each and look up examples on your own to understand each and where they are most useful.
Since you want to replace everything in your array I suggest using .map()
or .foreach() since these will loop through the whole array for you without you having to keep track of the index yourself. Below are examples of using each to implement what I think you are going for.
Map
function removeSpecial(str) {
// replace all these character with ' '
// \ " \b \f \r \t
str = str.replace(/[\\"\b\f\r\t]/g, ' ');
// replace / with -
str = str.replace(/\//g, '-');
// replace \n with ,
str = str.replace(/\n/g, ',');
return str;
}
let myArray = ["string\\other", "test/path"];
let withoutSpecial = myArray.map(removeSpecial); // ["string other", "test-path"]
forEach
function removeSpecial(myArray) {
let withoutSpecial = [];
myArray.forEach(function(str) {
str = str.replace(/[\\"\b\f\r\t]/g, ' ');
// replace / with -
str = str.replace(/\//g, '-');
// replace \n with ,
str = str.replace(/\n/g, ',');
withoutSpecial.push(str)
});
return withoutSpecial;
}
let myArray = ["string\\other", "test/path"];
let withoutSpecial = removeSpecial(myArray); // ["string other", "test-path"]
The internalals of each function's can be whatever replacements you need it to be or you could replace them with the function you already have. Map is stronger in this situation because it will replace the values in the array, it's used to map the existing values to new corresponding values one to one for every element. On the other hand the forEach solution requires you to create and add elements to a new array, this is better for when you need to do something outside the array itself for every element in the array.
PS. you should check out https://regex101.com/ for help building regular expressions if you want a more complex replacements but you dont really need them for this situation
I realize that the way I wrote my goal isn't exactly clear. I think what I should have said was that given several text strings, I want to strip out some specific characters (quotes, for example), and then output each of those into an array that can be accessed. I have read about arrays, it's just been my experience in learning JS that reading code and actually doing code are two very different things.
So I appreciate the references to documentation, what I really needed to see was a real life example code.
I ended up finding a solution that works:
function escapeData(data) {
return data
.replace(/\r/g, "");
}
var result = {};
result.what_hap_escaped = escapeData($what_hap);
result.desc_injury_escaped = escapeData($desc_injury);
result;
I appreciate everyone's time, and hope I didn't annoy you guys too much with my poorly constructed question :)

Using javascript regex to translate a html

I would like to build my own translation function in javascript.
I already have a function language.lookup(key) which translates a word or expression:
var frenchHello = language.lookup('hello') //'bonjour'
Now I would like to write a function which takes a html string and translates it with my lookup function. In the html string I will have a special syntax for example #[translationkey] that will point out that this word should be translated.
This is the result I want:
var html = '<div><span>#[hello]</span><span>#[sir]</span>'
language.translate(html) //'<div><span>bonjour</span><span>monsieur</span>
How would I write language.translate?
My idea is to filter out my special syntax with regex and then run language.lookup on each key. Maybe with string replace or something.
I suck when it comes to regex and I've only come up with a very incomplete example but I include it anyway so maybe someone get the idea of what I am trying to do. Then if there is a better but complete different solution that is more than welcome.
var value = "#[hello], nice to see you.";
lookup = function(word){
return "bonjour";
};
var res = new RegExp( "\\b(hello)\\b", "gi" ).exec(value)
for (var c1 = 0; c1 < res.length; c1++){
value = value.replace(res[c1], lookup(res[c1]))
}
alert(value) //#[bonjour], nice to see you.
The regex should of course not filter out the word hello but the syntax and then collect the key by grouping or similar.
Can anyone help?
Just use String.replace method's ability to call function specified as second argument to generate replacement text and make a global replace using regexp matching your syntax:
var value = "#[hello], #[sir], nice to see you.";
lookup = function(full_match, word){
if(word == 'hello')
return "bonjour";
if(word == 'sir')
return "monsieur"
};
console.log(value.replace(/#\[(.+?)\]/gi, lookup))
Result:
bonjour, monsieur, nice to see you.
Of course when your replacement list gets bigger, you'd better use lookup object instead of series of ifs in lookup function, but you can really do whatever you want there.
You can try this to find all occurrences:
var re = new RegExp('#\\[([^\\]]+?)\\]', 'gi'),
str = '#[value1] plain text #[value2]',
match;
while (match = re.exec(str)) {
console.log(match);
}
You could use something like:
#\\[[^\\]]*\\]
Which matches the hash followed by an opening square bracket followed by zero or more characters NOT including the closing square bracket, followed by a closed square bracket.
Alternatively, perhaps it would be better to handle the translation at the server side (maybe even through your template engine) and send back to your client the translated response. Otherwise, (depending on the specific problem you are dealing with of course), you might end up sending a lot of data to the browser which might make your application respond slowly.
EDIT:
Here is a working piece of code:
var q="This #[ANIMAL1] was eaten by that #[ANIMAL2]";
var u = {"#[ANIMAL1]":"Lion","#[ANIMAL2]":"Frog"};
function insertAnimal(aString, lookup){
var res = (new RegExp("#\\[[^\\]]*\\]", "gi"))
while (m = res.exec(aString)){
aString = aString.replace(m, lookup[m])
}
return aString;
}
function main(){
alert(insertAnimal(q,u));
}
You can call the "main()" from an HTML document's body onload event
I can compare your requirement to 'resolving template texts within content'. If it is feasible to use Jquery , you should try Handlebars.js
.

How to substring in jquery

How can I use jquery on the client side to substring "nameGorge" and remove "name" so it outputs just "Gorge"?
var name = "nameGorge"; //output Gorge
No jQuery needed! Just use the substring method:
var gorge = name.substring(4);
Or if the text you want to remove isn't static:
var name = 'nameGorge';
var toRemove = 'name';
var gorge = name.replace(toRemove,'');
Using .split(). (Second version uses .slice() and .join() on the Array.)
var result = name.split('name')[1];
var result = name.split('name').slice( 1 ).join(''); // May be a little safer
Using .replace().
var result = name.replace('name','');
Using .slice() on a String.
var result = name.slice( 4 );
Standard javascript will do that using the following syntax:
string.substring(from, to)
var name = "nameGorge";
var output = name.substring(4);
Read more here: http://www.w3schools.com/jsref/jsref_substring.asp
That's just plain JavaScript: see substring and substr.
You don't need jquery in order to do that.
var placeHolder="name";
var res=name.substr(name.indexOf(placeHolder) + placeHolder.length);
var name = "nameGorge";
name.match(/[A-Z].*/)[0]
Yes you can, although it relies on Javascript's inherent functionality and not the jQuery library.
http://www.w3schools.com/jsref/jsref_substr.asp
The substr function will allow you to extract certain parts of the string.
Now, if you're looking for a specific string or character to use to find what part of the string to extract, you can make use of the indexOf function as well.
http://www.w3schools.com/jsref/jsref_IndexOf.asp
The question is somewhat vague though; even just link text with 'name' will achieve the desired result. What's the criteria for getting your substring, exactly?
How about the following?
<script charset='utf-8' type='text/javascript'>
jQuery(function($) { var a=$; a.noConflict();
//assumming that you are using an input text
// element with the text "nameGorge"
var itext_target = a("input[type='text']:contains('nameGorge')");
//gives the second part of the split which is 'Gorge'
itext_target.html().split("nameGorge")[1];
...
});
</script>

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