An example of what im trying to get:
String1 - 'string.co.uk' - would return 'string' and 'co.uk'
String2 - 'random.words.string.co.uk' - would return 'string` and 'co.uk'
I currently have this:
var split= [];
var tld_part = domain_name.split(".");
var sld_parts = domain_name.split(".")[0];
tld_part = tld_part.slice(1, tld_part.length);
split.push(sld_parts);
split.push(tld_part.join("."));
With my current code, it takes the split parameter from the beginning, i want to reverse it if possible. With my current code it does this:
String1 - 'string.co.uk' - returns 'string' and 'co.uk'
String2 - 'random.words.string.co.uk' - would return 'random` and 'words.string.co.uk'
Any suggestions?
To expand upon elclanrs comment:
function getParts(str) {
var temp = str.split('.').slice(-3) // grabs the last 3 elements
return {
tld_parts : [temp[1],temp[2]].join("."),
sld_parts : temp[0]
}
}
getParts("foo.bar.baz.co.uk") would return { tld_parts : "co.uk", sld_parts : "baz" }
and
getParts("i.got.99.terms.but.a.bit.aint.one.co.uk") would return { tld_parts : "co.uk", sld_parts : "one" }
try this
var str='string.co.uk'//or 'random.words.string.co.uk'
var part = str.split('.');
var result = part[part.length - 1].toString() + '.' + part[part.length - 1].toString();
alert(result);
One way that comes to mind is the following
var tld_part = domain_name.split(".");
var name = tld_part[tld_part.length - 2];
var tld = tld_part[tld_part.length - 1] +"."+ tld_part[tld_part.length];
Depending on your use case, peforming direct splits might not be a good idea — for example, how would the above code handle .com or even just localhost? In this respect I would go down the RegExp route:
function stripSubdomains( str ){
var regs; return (regs = /([^.]+)(\.co)?(\.[^.]+)$/i.exec( str ))
? regs[1] + (regs[2]||'') + regs[3]
: str
;
};
Before the Regular Expression Police attack reprimand me for not being specific enough, a disclaimer:
The above can be tightened as a check against domain names by rather than checking for ^., to check for the specific characters allowed in a domain at that point. However, my own personal perspective on matters like these is to be more open at the point of capture, and be tougher from a filtering point at a later date... This allows you to keep an eye on what people might be trying, because you can never be 100% certain your validation isn't blocking valid requests — unless you have an army of user testers at your disposal. At the end of the day, it all depends on where this code is being used, so the above is an illustrated example only.
Related
I am new in programing and right now I am working on one program. Program need to find the substring in a string and return the index where the chain starts to be the same. I know that for that I can use "indexOf". Is not so easy. I want to find out substrings with at moste one different char.
I was thinking about regular expresion... but not really know how to use it because I need to use regular expresion for every element of the string. Here some code wich propably will clarify what I want to do:
var A= "abbab";
var B= "ba";
var tb=[];
console.log(A.indexOf(B));
for (var i=0;i<B.length; i++){
var D=B.replace(B[i],"[a-z]");
tb.push(A.indexOf(D));
}
console.log(tb);
I know that the substring B and string A are the lowercase letters. Will be nice to get any advice how to make it using regular expresions. Thx
Simple Input:
A B
1) abbab ba
2) hello world
3) banana nan
Expected Output:
1) 1 2
2) No Match!
3) 0 2
While probably theoretically possible, I think it would very complicated to try this kind of search while attempting to incorporate all possible search query options in one long complex regular expression. I think a better approach is to use JavaScript to dynamically create various simpler options and then search with each separately.
The following code sequentially replaces each character in the initial query string with a regular expression wild card (i.e. a period, '.') and then searches the target string with that. For example, if the initial query string is 'nan', it will search with '.an', 'n.n' and 'na.'. It will only add the position of the hit to the list of hits if that position has not already been hit on a previous search. i.e. It ensures that the list of hits contains only unique values, even if multiple query variations found a hit at the same location. (This could be implemented even better with ES6 sets, but I couldn't get the Stack Overflow code snippet tool to cooperate with me while trying to use a set, even with the Babel option checked.) Finally, it sorts the hits in ascending order.
Update: The search algorithm has been updated/corrected. Originally, some hits were missed because the exec search for any query variation would only iterate as per the JavaScript default, i.e. after finding a match, it would start the next search at the next character after the end of the previous match, e.g. it would find 'aa' in 'aaaa' at positions 0 and 2. Now it starts the next search at the next character after the start of the previous match, e.g. it now finds 'aa' in 'aaaa' at positions 0, 1 and 2.
const findAllowingOneMismatch = (target, query) => {
const numLetters = query.length;
const queryVariations = [];
for (let variationNum = 0; variationNum < numLetters; variationNum += 1) {
queryVariations.push(query.slice(0, variationNum) + "." + query.slice(variationNum + 1));
};
let hits = [];
queryVariations.forEach(queryVariation => {
const re = new RegExp(queryVariation, "g");
let myArray;
while ((searchResult = re.exec(target)) !== null) {
re.lastIndex = searchResult.index + 1;
const hit = searchResult.index;
// console.log('found a hit with ' + queryVariation + ' at position ' + hit);
if (hits.indexOf(hit) === -1) {
hits.push(searchResult.index);
}
}
});
hits = hits.sort((a,b)=>(a-b));
console.log('Found "' + query + '" in "' + target + '" at positions:', JSON.stringify(hits));
};
[
['abbab', 'ba'],
['hello', 'world'],
['banana', 'nan'],
['abcde abcxe abxxe xbcde', 'abcd'],
['--xx-xxx--x----x-x-xxx--x--x-x-xx-', '----']
].forEach(pair => {findAllowingOneMismatch(pair[0], pair[1])});
I come from C++ background and currently working on node.js server app.
I want to know if there exists an equivalent of find_first_of C++ string class method in Javascript string.
Basically I'll have a string like
var str ="abcd=100&efgh=101&ijkl=102&mnop=103". The order of & seprated words could be random. So, I wanted to do something like the following:
str.substr(str.find("mnop=") + string("mnop=").length, str.find_first_of("&,\n'\0'")
Is there a way to it in a single line like above?
You may find the search function useful.
"string find first find second".search("find"); // 7
In addition, you may also find this question useful.
There's no direct equivalent, but you always can employ regular expressions:
var str ="abcd=100&efgh=101&ijkl=102&mnop=103";
console.log(str.match(/&mnop=([^&]+)/)[1]);
However, in this specific case, it's better to use the dedicated module:
var qs = require('querystring');
var vars = qs.parse(str);
console.log(vars.mnop);
If you really want a method that behaves like find_first_of, it can be implemented like this:
String.prototype.findFirstOf = function(chars, start) {
var idx = -1;
[].some.call(this.slice(start || 0), function(c, i) {
if(chars.indexOf(c) >= 0)
return idx = i, true;
});
return idx >= 0 ? idx + (start || 0) : -1;
}
console.log("abc?!def??".findFirstOf('?!')); // 3
console.log("abc?!def??".findFirstOf('?!', 6)); // 8
Using javascript, im trying to make a node.js module to parse predicate logic statements.
I've been working on this regex for a bit and I just can't get it to behave the way i want
1. /\(((?:[^{}]*\([^{}]*\))*[^{}]*?)\)/
2. .replace(/\)((?:[^{}]*\)[^{}]*\))*[^{}]*?)\(/,'):::(')
the latter works fine on things like (a&s&d&a&s&d)->(a&s&(d)&s|(d)) but i just switched the delimiters...
what I'm trying to do is change a statement like
((r|a)&(s|r))&(~r)->(r|(q&r))->q
into
1->2->q
I can certainly write a procedural function to do it, that would be a fine solution. But Im really stuck on this.
The only real specification is the regex needs to respect the outermost parenthesis the most, and be able to replace separate ones.
Because this is not regex friendly I put togethor a couple of functions that do what you are looking for. The first matches parenthesis with depth:
function match_parens(code_to_test, level, opening, closing){
var sub_match, matched;
return code_to_test.replace(new RegExp('^([^'+opening+closing+']*(.))[\\s\\S]*$'), function(full_match, matched, $2, offset, original){
if ($2 == opening){
sub_match = match_parens(original.substr(offset+matched.length), level + 1, opening, closing);
matched = matched + sub_match
}
else if (level > 1){
sub_match = match_parens(original.substr(offset+matched.length), level - 1, opening, closing);
matched += sub_match;
}
return matched;
});
}
This function takes a string and returns everything up until the closing element.
The next function helps pulls a string passed to it apart, replacing all content in parenthesis with escalating numbers:
function pull_apart(testString){
var count = 1,
returnString = '',
tempIndex = testString.indexOf('(');
while (tempIndex !== -1){
returnString += testString.substring(0,tempIndex)+count;
count += 1;
testString = testString.substring(testString.indexOf('(') + match_parens(testString.substr(tempIndex + 1), 1, '(', ')').length+1)
tempIndex = testString.indexOf('(');
}
returnString += testString;
return returnString;
}
Running pull_apart('((r|a)&(s|r))&(~r)->(r|(q&r))->q') returns "1&2->3->q", which is what you are looking for. While this is not entirely regex, it is utilized in the paren matching function up above. I'm not sure if this fits whatever use case you had in mind, but hopefully it helps.
Here is an example of url structure I'll be working with (ignore the age of electric video :) )
http://www.youtube.com/embed/ABCumLrphFA?&start=20&end=50
Basically I want to be able to grab the video id, the chosen start time (20) and end chosen time (50) and save them as variables from any URL that follows the pattern above.
So a simple setup is this:
var url = 'http://www.youtube.com/embed/ABCumLrphFA?&start=20&end=50'
// get youtube id
function youtubeid(url) {
var ytid = url.match(dont know);
ytid = ytid[1];
return ytid;
}
// get youtube start time
function youtubeStart(url) {
var ytStart = url.match(dont know);
ytStart=ytStart[1];
return ytStart;
}
// get youtube end time
function youtubeEnd(url) {
var ytEnd = url.match(dont know);
ytEnd=ytEnd[1];
return ytEnd;
}
If you could help me fill in the blanks that would be most amazing. I've been staring at regex documentation for a while now and just getting more and more confused.
This other Stack Overflow answer may help you. I used Peter Mortensen's answer below.
Get query string values in JavaScript
To obtain the actual YouTube Id, you can use this regular expression:
http:\/\/www.youtube.com\/embed\/(.{11})
That regex will return the value in parenthesis. You can test it here:
http://www.pagecolumn.com/tool/regtest.htm
Sample code:
var url = 'http://www.youtube.com/embed/ABCumLrphFA?&start=20&end=50'
// get youtube id
function youtubeid(url) {
var ytid = url.match(/http:\/\/www.youtube.com\/embed\/(.{11})/);
ytid = ytid[1];
return ytid;
}
alert(youtubeid(url));
function getParameterByName(name, url) {
var match = RegExp('[?&]' + name + '=([^&]*)')
.exec(url);
return match && decodeURIComponent(match[1].replace(/\+/g, ' '));
}
alert(getParameterByName('start', url));
alert(getParameterByName('end', url));
1
/http:\/\/www\.youtube\.com\/embed\/([^?]+)/
2
/http:\/\/www\.youtube\.com\/embed\/[^?]+.*[?&]start=(\d+)(?:&|$)/
3
/http:\/\/www\.youtube\.com\/embed\/[^?]+.*[?&]end=(\d+)(?:&|$)/
This'll only work if you know your URLs will look exactly like the one you gave (no extra query parameters; start and end always in that order; no HTTPS; etc.). But you can get them all at once:
js> str = 'http://www.youtube.com/embed/ABCumLrphFA?&start=20&end=50'
http://www.youtube.com/embed/ABCumLrphFA?&start=20&end=50
js> rxp = /http:\/\/www.youtube.com\/embed\/(.*)\?&start=(\d+)?&end=(\d+)?/
/http:\/\/www.youtube.com\/embed\/(.*)\?&start=(\d+)?&end=(\d+)?/
js> result = rxp.exec(str)
http://www.youtube.com/embed/ABCumLrphFA?&start=20&end=50,ABCumLrphFA,20,50
js> result[0]
http://www.youtube.com/embed/ABCumLrphFA?&start=20&end=50
js> result[1]
ABCumLrphFA
js> result[2]
20
js> result[3]
50
I believe it's possible to write a regex that can cope with all the quirks I mentioned above, but it's way uglier and makes it harder to understand. Anyway - hope this helps!
See also: JavaScript Regex Escape Sequences and JavaScript Regex Methods
var url = "http://www.youtube.com/embed/ABCumLrphFA?&start=20&end=50";
// get youtube id
function youtubeid(url) {
q = url.substring(url.lastIndexOf("/")+1);
var ytid = q.substring(q.lastIndexOf("?"), -1);
return ytid;
}
// get youtube start time
function youtubeStart(url) {
q = url.substring(url.lastIndexOf("/")+1);
var ytStart = q.substring(q.indexOf("&start")+7,q.indexOf("&end"));
return ytStart;
}
// get youtube end time
function youtubeEnd(url) {
q = url.substring(url.lastIndexOf("/")+1);
var ytEnd = q.substring(q.indexOf("&end")+5);
return ytEnd;
}
console.log(youtubeid(url));
console.log(youtubeStart(url));
console.log(youtubeEnd(url));
To retrieve the id
url.match(/embed\/(.*)\?/)
The best way to retrieve URL params (start and end) is to do something like Get Querystring with Dojo Then you could use the following to retrieve start and end
var qs = getUrlParams();
console.log("start is " + qs.start + " and end is " + qs.end )
The problem statement is like this: I have a contract. On renewal on every month the contract name should append with renewal identifier. For example at beginning the name is myContract then on first renewal name should be myContract-R1, next renewal name should be myContract-R2 and so on.. On each renewal, the name should automatically change. So in Jquery how can I do this?
This is a JavaScript question, not a jQuery question. jQuery adds little to JavaScript's built-in string manipulation.
It sounds like you want to take a string in the form "myContract" or "myContract-Rx" and have a function that appends "-R1" (if there's no "-Rx" already) or increments the number that's there.
There's no shortcut for that, you have to do it. Here's a sketch that works, I expect it could be optimized:
function incrementContract(name) {
var match = /^(.*)-R([0-9]+)$/.exec(name);
if (match) {
// Increment previous revision number
name = match[1] + "-R" + (parseInt(match[2], 10) + 1);
}
else {
// No previous revision number
name += "-R1";
}
return name;
}
Live copy
You can use a regular expression for this:
s = s.replace(/(-R\d+)?$/, function(m) {
return '-R' + (m.length === 0 ? 1 : parseInt(m.substr(2), 10) + 1);
});
The pattern (-R\d+)?$ will match the revision number (-R\d+) if there is one (?), and the end of the string ($).
The replacement will return -R1 if there was no revision number before, otherwise it will parse the revision number and increment it.
how you get renewal number? Calculating from date, or getting from database?
var renewal = 1,
name = 'myContract',
newname = name+'R'+renewal;
or maybe like
$(function(){
function renew(contract){
var num_re = /\d+/,
num = contract.match(num_re);
if (num==null) {
return contract+'-R1';
} else {
return contract.replace(num_re,++num[0]);
}
}
var str = 'myContract';
new_contract = renew(str); // myContract-1
new_contract = renew(new_contract); // myContract-2
new_contract = renew(new_contract); // myContract-3
});
Here jQuery can't help you. It's pure JavaScript working with strings
P.S. I have here simple reg exp, that's not concrete for your example (but it works). Better use reg-exp from example of T.J. Crowder