Contents
Operators[edit | edit source]
'==' or '==='[edit | edit source]
Крайне рекомендуется использовать только операторы строгого равенства
used in #indexOf
iif, .?[edit | edit source]
null-coalescing as logical ||
&&, ||[edit | edit source]
&& evaluates as long as the statement is true. If it is true, it returns the last value. If it is false, it returns the first value that evaluated to false. That may be 0, null, false etc. || returns the first value that evaluates to true.
Types casting[edit | edit source]
!!myString; // convert to bool
+myString; // convert to number
~~myNumber; // double NOT bitwise operator is faster substitute for Math.floor()
TypeScript vs CSharp[edit | edit source]
any is like dynamic and unknown is like object
typeof[edit | edit source]
- Array.isArray
Strings[edit | edit source]
use Regex where possible
- substring
String method substring or slice
- last characters
/substring$/.test(str)
- last n characters
slice.(0, -n) - allows you to make the second argument negative
Hashed lists and dictionaries[edit | edit source]
the JavaScript Object is implemented with a hash table iteration may be done by for(let key in dict)
Remove property from object[edit | edit source]
Loops[edit | edit source]
in TypeScript iteration over elements is for(let i of list) construction
Filter[edit | edit source]
- Array.prototype.filter
good support
- Array.prototype.find - returns the value of the first element in the array that satisfies the provided testing function
bad support: no IE, Safari 7.1
Methods[edit | edit source]
toFixed[edit | edit source]
toFixed() з javascript використовуємо лише для внутрішніх розрахунків, для презентаційних цілей (показати юзеру) її ніззя, бо вона не враховує регіональні налаштування формату чисел
DOM and browser[edit | edit source]
querySelector[edit | edit source]
good support including Safari 3.1+, or IE8+
getBoundingClientRect[edit | edit source]
good support
Page redirect[edit | edit source]
як правильно зробити редірект через window.location
- GetAppRoot() - кастомна ЖС функція
- window.location.search
asynchronous[edit | edit source]
setTimeout и setInterval... Рекурсивный setTimeout позволяет задать задержку между выполнениями более точно, чем setInterval.[edit | edit source]
Event Loop[edit | edit source]
async/await[edit | edit source]
bad support, no IE, no Windows 8.1, but polyfilled in core-js
Pages in category "JS coding guide"
The following 6 pages are in this category, out of 6 total.