Мангин Александр
var student = {
wakeUp: function() {
console.log('Я НЕ СПЛЮ!');
};
};
student.wakeUp();
// 'Я НЕ СПЛЮ!'
var answer = 42;
answer.toFixed(2);
// 42.00
var answer = 42;
answer.toFixed(2);
var answer = 42;
(new Number(answer)).toFixed(2);
var answer = 42;
answer.secret = 'немного магии';
answer.secret;
undefined;
var answer = 42;
(new Number(answer))
.secret = 'немного магии';
answer.secret;
undefined;
var answer = new Number(42);
answer.secret = 'немного магии';
answer.secret;
'немного магии';
var answer = '42';
Number(answer);
// 42
var answer = '42';
var result = new Number(answer);
result;
// Number {[[PrimitiveValue]]: 42}
var answer = '42';
var result = new Number(answer);
result == 42;
result === 42;
typeof result;
// true
// false
// object
var isChecked = new Boolean(false);
if (isChecked) {
console.log('checked');
} else {
console.log('unchecked');
}
// checked
var empty = {};
var driver = {
'first name': 'Max',
skills: {
mad: 1000
}
};
var empty = new Object();
var empty = Object.create(null);
var student = {
id: 1,
'full name': 'Alex'
};
student.id;
student['id'];
student['full name'];
// 1
// 1
// 'Alex'
var student = {
id: 1,
'full name': 'Alex'
};
student.score = 1;
student['score'] = 1;
student['full name'] = 'Max;
var student = {
id: 1,
'full name': 'Alex'
};
student.score;
student.score.toFixed(2);
// undefined
// TypeError
var student = {
id: 1,
score: 1,
'full name': 'Alex'
};
delete student.score;
var student = {
id: 1,
score: 1,
'full name': 'Alex'
};
'id' in student;
student.hasOwnProperty('score');
var student = {
name: 'Alex',
surname: 'Mangin'
};
var student = {
getFullName: function() {
return this.name +
' ' + this.surname;
},
setFullName: function (value) {
var parts = value.split(' ');
this.name = parts[0];
this.surname = parts[1];
}
};
student.getFullName();
student.setFullName('Max Maxes');
var student = {
get fullName() {
return this.name +
' ' + this.surname;
},
set fullName(value) {
var parts = value.split(' ');
this.name = parts[0];
this.surname = parts[1];
}
};
student.fullName;
student.fullName = 'Max Maxes';
var student = {
name: 'Alex',
surname: 'Mangin'
};
Object.defineProperty(student,
'score', {value: 42});
student.score = 42;
var student = {
name: 'Alex',
surname: 'Mangin'
};
Object.defineProperty(student,
'score', {
value: 42,
configurable: false
});
delete student.score;
student.score; // 42
var student = {};
Object.defineProperty(student,
'score', {
value: 42,
enumerable: false
});
Object.keys(student); // []
for (var x in student) {
console.log(x);
}
var student = {
name: 'Alex',
surname: 'Mangin'
};
Object.defineProperty(student,
'score', {
value: 100500,
writable: false
});
student.score = 0;
student.score; // 100500
var student = {
_score: 0
};
Object.defineProperty(student,
'score', {
set: function (rawValue) {...},
get: function () {...}
});
Object.defineProperty({},
'score', {
configurable: false,
enumerable: false,
writable: false,
value: undefined,
set: undefined,
get: undefined
});
Object.defineProperty({},'score',
{
configurable: true,
enumerable: true,
writable: true,
value: 'Ваше значение',
set: undefined,
get: undefined
});
var fns = Array.prototype;
var define = Object.defineProperty;
fns.forEach = function () {
// ваша реализация
}
define(fns, 'forEach', {
value: function() {};
enumerable: false,
writable: true,
configurable: true
});
var student = {
name: 'Alex',
surname: 'Mangin'
}
JSON.stringify(student);
// {"name":"Alex",
// "surname":"Mangin"}
var student = {
privateData: {secret: '42'}
}
JSON.stringify(student,
function (key, value) {
if (key === 'privateData') {
return null;
}
return value;
});
// {"privateData":null}
var student = {};
student.self = student;
JSON.stringify(student);
// Uncaught TypeError: Converting
// circular structure to JSON
var student = {
print: function () {
console.log('Mangin Alex');
},
regexp: /d+/
};
JSON.stringify(student);
{"regexp":{}}
var rawStudent = '{"name":"Alex"}';
JSON.parse(rawStudent);
var rawStudent='{"name":"Alex", ' +
'"_meta"="student"}';
function deserialize (key, value) {
if (key === '' &&
value._meta === 'student') {
return createStudent(value);
}
return value;
}
JSON.parse(rawStudent, deserialize);
var numbers = [1, 1, 2, 3, 5];
for (var i = 0 ; i < 5; i ++) {
console.log(numbers[i]);
});
numbers.forEach(function (n) {
console.log(n);
});
var numbers = [1, 1, 2, 3, 5];
var result = []
for (var i = 0 ; i < 5; i ++) {
result.push(numbers[i]*numbers[i])
});
var result = numbers.map(function (n) {
return n*n;
});
var numbers = [1, 1, 2, 3, 5];
var result = []
for (var i = 0 ; i < 5; i ++) {
if (numbers[i] % 2 === 0) {
result.push(numbers[i]);
break;
}
});
var result = numbers.filter(function (n) {
return n % 2;
});
var numbers = [1, 1, 2, 3, 5];
var isBiggerThanTen = false;
for (var i = 0 ; i < 5; i ++) {
if (numbers[i] > 10) {
isBiggerThanTen = true;
break;
}
});
var result = numbers.some(function (n) {
return n > 10;
});
var numbers = [1, 1, 2, 3, 5];
var isBiggerThanTen = true;
for (var i = 0 ; i < 5; i ++) {
if(numbers[i] >= 10) {
isBiggerThanTen = false;
break;
}
});
var numbers = [1, 1, 2, 3, 5];
var result = numbers.every(function (n) {
return n < 10;
});
var numbers = [1, 1, 2, 3, 5];
var dict = {};
for (var i = 0 ; i < 5; i ++) {
dict[i] = numbers[i]*numbers[i];
});
function callback(dict, value) {
dict[value] = value * value;
return dict;
}
var result =
numbers.reduce(callback, {});
var now = new Date();
// 24 часа после 01.01.1970 GMT+0
var jan02_1970
= new Date(3600 * 24 * 1000);
var now = new Date(year, month,
date, hours, minutes,
seconds, ms);
// year > 1970
// month >= 0
var date = new Date();
date.getFullYear(); // год
date.getMonth(); // месяц
date.getDate(); // день
date.getHours(); // час
date.getMinutes(); // минуты
date.getSeconds(); // секунды
date.getMilliseconds(); // милисекунды
date.getDay(); // день недели
var date = new Date();
date.getUTCFullYear(); // год
date.getUTCMonth(); // месяц
date.getUTCDate(); // день
date.getUTCHours(); // час
date.getUTCMinutes(); // минуты
date.getUTCSeconds(); // секунды
date.getUTCMilliseconds(); // милисекунды
date.getUTCDay(); // день недели
var date = new Date();
date.getTime();
var date = new Date();
date.getTimezoneOffset(); // -300
Date.now(); // 1446448043192
var date = new Date();
date.setFullYear(2014);
date.setMonth(2);
date.setDate(12);
date.setHours(10);
date.setMinutes(23);
date.setSeconds(60);
date.setMilliseconds(500);
var date = new Date(2013, 0, 32);
// 32 января 2013 ?!?
date;
// ... это 1 февраля 2013!
var start = Date.now()
// ваш код
var end = Date.now();
console.log(end - start);
console.time('test1')
// ваш код
console.timeEnd('test1');
var date = Date.parse('some date');
Date.parse('2012-01-26'+
'T13:51:50.417');
Date.parse('2012-01-26');
Date.parse('2012-01-26'+
'T13:51:50.417Z10:30');
Math.E; // 2,718
Math.LN2; // ln 2 0,693.
Math.LN10; // ln 10 2.303.
Math.LOG2E; // log(2, e) 1.443
Math.LOG10E; // log(10, e) 1.443
Math.PI; // 3.14
Math.SQRT1_2; // sqrt(1/2) 0,707.
Math.SQRT2; // sqrt(2) 1.414
Math.sign(x);
Math.abs(x);
Math.floor(x);
Math.round(x);
Math.log(x);
Math.max(a,b,c, ...);
Math.min(a,b,c ...;
Math.random();
Math.sqrt(x);
Math.cos(x);
Math.sin(x);
Math.tan(x);