The avatar for @solovevserg
Sergei Solovev
Co-founder of SDAL, Analysts and frontend team-lead in Qoollo, Student in BMSU, Moscow, Bachata dancer ;)
Published
Интенсив по JS
Edited
Nov 26, 2021
Fork of Переменные, типы данных, арифметика, объекты и коллекции
1 star
Интенсив по JS
JS интенсив от Сергея СоловьеваЧто такое JS и как он такой получился (1/9)Среда выполнения JS (2/9)
Переменные и типы данных (3/9)
Синтаксис и управляющие конструкции (4/9)Функции и функциональное программирование в JavaScript (5/9)Окружения, блоки, вызовы функций, замыкания (6/9)Классы и ООП, прототипное наследование, this (7/9)Работа с асинхронным кодом и Promise (8/9)Экосистема JS и NPM (9/9)
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({
str: typeof "Вау, строка",
num: typeof 76.342,
bool: typeof true,
symbol: typeof Symbol("sym"),
null: typeof null,
undef: typeof obj.notExist,
bigint: typeof 1234567890123456789012345678901234567890n
})
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function a() {
console.log(b); // undefined
if (true) {
console.log(b); // unedfined
var b = 2;
console.log(b); // 2
}
console.log(b); // 2
}
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7.3e9
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0.1 + 0.2 == 0.3
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0.1 + 0.2
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(0.1 + 0.2).toFixed(2)
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parseInt('100px')
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parseInt('a123')
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parseFloat('12.5em')
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Infinity
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"double, " + "single, " + `backticks`
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`Пример интерполяции ${ "строки".toUpperCase() }`
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"\u{1F60D} JS 🔥 \u00A9"
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{
let str = "Hi";
str[0] = "h"; // ошибка
}
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Number("123")
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+"123"
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String(321)
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Boolean(1)
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Boolean("")
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Boolean("string")
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7 + 2

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7 - 6
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4 * 32
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5 / 2
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7 % 4
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5**3
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-2
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fastSum(5, 2)
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fastMult(3, 9)
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function fastSum(n, m) {
return n += m;
}
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function fastMult(n, m) {
return n *= m;
}
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Math.floor(3.1)
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Math.floor(-1.1)
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Math.ceil(3.1)
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Math.ceil(-1.1)
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Math.round(3.1)
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Math.round(3.6)
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Math.round(-1.1)
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Math.trunc(3.1)
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Math.trunc(-1.1)
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8 >= 8
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5 != 3 + 4 - 2
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3 == "3"
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3 === "3"
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9 > 0
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5 > 3 || 5 < 7
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4 < 4 || 4 > 6
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5 == 5 && 2 > 3
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5 == 5 && 2 >= 2
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!(5 > 2)
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!(17 < 13)
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"2" || "4"
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## Встроенные типы коллекций
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