-5
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Recreational languages win at code golf too much. This challenge is simple, when using higher level functions.

The task is as follows:

Given any valid url, which is guaranteed to result in a valid HTML document (for example https://en.wikipedia.org/wiki/Ruby_on_Rails, which has 9 images), count the number of images displayed from the resultant webpage.

Only images visible in the HTML code are counted, marked by the HTML <img> tag.

Websites that can continually load images (Google Images) are not valid tests.

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closed as unclear what you're asking by NoOneIsHere, caird coinheringaahing, Sriotchilism O'Zaic, Stephen Leppik, Toto Apr 10 '18 at 17:49

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • \$\begingroup\$ Comments are not for extended discussion; this conversation has been moved to chat. \$\endgroup\$ – Mego Apr 12 '18 at 12:47
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    \$\begingroup\$ This is code-golf, right? The shortest code wins, right? Then why does a 61 byte answer beat an 10 byte answer? If my answer is invalid in some way, just comment on my post. \$\endgroup\$ – NoOneIsHere Apr 13 '18 at 22:55
2
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JavaScript, 61 bytes

As per this consensus, the code needs to run under the same domain as the page being requested, to avoid CORS issues. Returns a Promise conatining the count.

u=>fetch(u).then(r=>r.text()).then(t=>t.split`<img`.length-1)

Thanks to tsh for pointing out some code I forgot to update before posting, saving 3 bytes.


Try it

(f=
u=>fetch(`https://crossorigin.me/`+u).then(r=>r.text()).then(t=>t.split`<img`.length-1)
)(i.value=`https://codegolf.stackexchange.com/questions/161669/`).then(x=>o.innerText=x);b.addEventListener(`click`,_=>f(i.value).then(x=>o.innerText=x),0)
<input id=i><button id=b>Count</button><pre id=o></pre>

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  • \$\begingroup\$ Why not .match? or .split"<img"? \$\endgroup\$ – tsh Apr 10 '18 at 11:05
  • \$\begingroup\$ .match works out longer in order to handle the case of their being no images. You're right on the second count, though; forgot to change it before posting. Thanks. \$\endgroup\$ – Shaggy Apr 10 '18 at 11:07
  • \$\begingroup\$ *there! Dunno how I did that! \$\endgroup\$ – Shaggy Apr 10 '18 at 22:12
2
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CJam, 10 bytes

lg"<img"e=

Does not work online.

Description:

l          # read line
 g         # open url and get html
  "<img"   # this string
        e= # count arg2 in arg1
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  • 1
    \$\begingroup\$ @downvoters what did I do wrong? \$\endgroup\$ – NoOneIsHere Apr 10 '18 at 4:13
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    \$\begingroup\$ No idea. / Anyone who hates golfing languages is likely to know none of them. (otherwise they would know how hard it is to golf in those languages) Bash is not even a golfing language... \$\endgroup\$ – user202729 Apr 10 '18 at 4:53
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    \$\begingroup\$ Can you add a TIO and/or an explanation? I don't know CJam and can't figure out how this is reading in the HTML. \$\endgroup\$ – Shaggy Apr 10 '18 at 9:39
2
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Python 3 + Selenium + Firefox, 124 bytes

from selenium.webdriver import*
d=Firefox()
d.get(input())
c=len(d.find_elements_by_xpath('//img'))
d.quit()
print(c)

Notice that https://en.wikipedia.org/wiki/Ruby_on_Rails report 8 instead of 9. This is due to one of the <img> tag is contained by <noscript>, which is regarded as comment by a browser who enabled script.

Changing webdriver.Firefox to webdriver.Ie may save 5 bytes... But I just dislike IE.

How to run:

  • First install Python 3, and Firefox
  • install Selenium by pip install selenium
  • Download gecko driver and put it to your path
  • Run this script
  • A Firefox will be started, ignore it and input the url to stdin
  • The result will be shown on stdout
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  • \$\begingroup\$ A manual count confirms that there are 9 img tags on that page. \$\endgroup\$ – Shaggy Apr 10 '18 at 9:38
  • \$\begingroup\$ @Shaggy One of them is in <noscript> tag which will not be rendered if browser support javascript; 3 of them are invisible to user. So there are 5 image displayed. \$\endgroup\$ – tsh Apr 10 '18 at 9:55
  • \$\begingroup\$ "Only images visible in the HTML code are counted, marked by the HTML <img> tag." \$\endgroup\$ – Shaggy Apr 10 '18 at 9:56
  • \$\begingroup\$ Yes, and also "count the number of images displayed from the resultant webpage". I read this as "only displayed <img> tags are count. \$\endgroup\$ – tsh Apr 10 '18 at 9:59
  • \$\begingroup\$ You're right, there's a contradiction there. I suggest asking for clarification. \$\endgroup\$ – Shaggy Apr 10 '18 at 10:01
1
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Python 2 + BeautifulSoup, 103 bytes

import bs4 as B
import urllib as U
print len(B.BeautifulSoup(U.urlopen(input()).read()).findAll('img'))

Can't do a TIO as BeautifulSoup is not available there. This reports 9 for https://en.wikipedia.org/wiki/Ruby_on_Rails.

Note: A warning is displayed before the number as a parser is not specified and lxmlis taken as the default. Adding the lxml parser explicitly suppresses the warning but costs another 7 bytes.

import bs4 as B
import urllib as U
print len(B.BeautifulSoup(U.urlopen(input()).read(),'lxml').findAll('img'))
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-1
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Bash, grep, and wc, 45 28 bytes

curl $1|grep -o "<img"|wc -l

-17 bytes thanks to tsh

Explanation:

curl $1                      # download html from first parametre
       |grep -o "<img"       # find all <img strings
                      |wc -l # count lines
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  • 3
    \$\begingroup\$ What if there are multiple <img> tags on a line? \$\endgroup\$ – nimi Apr 9 '18 at 23:06
  • \$\begingroup\$ @downvoters what did I do wrong? \$\endgroup\$ – NoOneIsHere Apr 10 '18 at 4:13
  • \$\begingroup\$ grep -o '<img' should works if you just want <img substring. \$\endgroup\$ – tsh Apr 10 '18 at 7:00
  • \$\begingroup\$ @nimi - if that's the case then the person who made the web site should be a code golfer and not a web developer :-) \$\endgroup\$ – ElPedro Apr 10 '18 at 20:25
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    \$\begingroup\$ @ElPedro No need of code golfer, just a minify tool should be enough. \$\endgroup\$ – tsh Apr 11 '18 at 4:51

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