☰ Contents · Computing

Links between web pages. Control work

Lessons 25–26 · 2 lessons · N. I. Taylaqov (general editor), A. B. Akhmedov, M. D. Pardayeva, A. A. Abdug‘aniyev, U. M. Mirsanov. Informatics and Information Technologies, Grade 11, 1st edition. “Extremum-press”, Tashkent, 2018
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Control work

Textbook: p. 90
GoalChecks what has been learnt in lessons 18–25 of Chapter II (web page, tools, pictures, forms, animation, sound and video, links) in control tasks.
New words
structure of the page / its appearance / its behaviour · HTML / CSS / JSalt text: a text description of a picture for people who cannot see it · alt matnframe rate: the number of frames shown per second (fps) · kadr tezligibit calculation: finding file size from pixels or samples and bits · bitlar hisobi
Explanation

This control work covers Chapter II. The theory questions are about the web page, site and domain, HTML tags, CSS, pictures and alt text, forms and validation, animation and frame rate, sound, and links. The practical task is to build one page: a heading, a picture (with alt), a form, a link and a menu; save the file as UTF-8 and check it by opening it in a browser. The calculations include picture size (width·height·3 bytes, 24-bit colour), animation frames (rate·seconds), sound size (rate·bit depth·channels·seconds : 8) and speed (distance : time). To prepare: write a list of tags and attributes, recall each tag with a one-line example, test your code with the F12 console, and repeat the safety rules (do not send a password openly through a form, do not use pictures without permission, do not click a suspicious link).

Worked examples
Sample calculations: an 800×600 pixel 24-bit picture is 800·600·3 = 1440000 bytes; at 12 frames/s a 5-second animation has 12·5 = 60 frames; mono, 8000 Hz, 16 bits, 5 seconds: 8000·16·5/8 = 80000 bytes.
A sample practical task: in the file klub.html put an h1 heading, a picture with alt text, a form with name and age fields (min and max for the age), a “Home” link and a nav menu; save the file as UTF-8.
Class activity

“Bug hunters”: a teacher or classmate prepares a page with 5 mistakes (no alt, an unclosed tag, a wrong relative address, a fixed width, an @keyframes name that does not match); another group finds and fixes them.

Practice
1
How many bytes is a 1000×500 pixel, 24-bit picture?
2
How many frames are in an 8-second animation at 25 frames/s?
3
Find and fix the problem in this line: <img src="gul.png">
4
Write the job of HTML, CSS and JavaScript in one sentence each.