By GokiSoft.com|
10:02 20/12/2021|
Học JS
[Video] Tìm hiểu Function, Array, Object trong JS - Khóa học lập trình Javascript - C2108G3
#vidu.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title></title>
</head>
<body>
<script type="text/javascript">
//Phan 1: Function
function tinhtong(n) {
//sum = 1 + 2 + 3 + ... + n
sum = 0
for(i=1;i<=n;i++) {
sum += i
}
console.log(sum)
document.write('<br/>sum = ' + sum)
}
tinhtong(10)
function cong(x, y) {
return x + y
}
tong = cong(5, 8)
console.log('tong: ' + tong)
//Phan 2: Array
//Khai niem: length -> so phan tu trong mang, index: 0 -> length - 1
//Phan 2.1
//B1. Khai bao mang
var arr1 = []
var arr2 = new Array()
//B2. Them phan tu vao trong mang
arr1.push(12) //so phan tu trong mang = 1
arr1.push(1) //so phan tu trong mang = 2
arr1.push(102) //so phan tu trong mang = 3
console.log(arr1)
//B3. Lay phan tu trong mang
console.log(arr1[0])
console.log(arr1[1])
for(i=0;i<arr1.length;i++) {
console.log(`arr1[${i}] = ${arr1[i]}`)
}
//B4. Xoa phan tu ra khoi mang -> xoa phan tu index = 1
arr1.splice(1, 1)
console.log(arr1)
//B5. Chen 1 phan tu vao mang -> chen vao vi tri index = 1
// arr1.splice(1, 0, 113, 114, 115)
// arr1.splice(1, 0, 6)
arr1.splice(1, 0, 0)
console.log(arr1)
//Phan 2.2
var arr3 = [5, 2, 1, 20, 11]
console.log(arr3)
arr3.push(100)
console.log(arr3)
//Mang -> cho phep quan ly nhieu kieu du lieu khac nhau
var arr4 = [5, true, 6.5, 'SINH VIEN', 'OKOK', 5]
console.log(arr4)
//Phan 3: Object
//int, number, float, String, char
//TH: bieu dien thong tin cua 1 doi tuong nao do: sinh vien, dong vat, xe co
//sinh vien -> nghi toi cac thuoc tinh: ten, tuoi, dia chi, email, sdt, .v.v
//xe co -> nghi toi cac thuoc tinh: ten, hang xe, mau xe, .v.v
//fullname, age, email -> field, thuoc tinh, properties, key
//doi tuong std (trong js) => quan ly theo kieu key -> value
var std = {
"fullname": "TRAN VAN DIEP",
"age": 12,
"email": "abc@gmail.com"
}
//Truy cap de lay gia tri cua cac thuoc tinh trong doi tuong (js)
console.log('fullname: ' + std['fullname'])
console.log('age: ' + std['age'])
console.log('email: ' + std['email'])
console.log('fullname: ' + std.fullname)
console.log('age: ' + std.age)
console.log('email: ' + std.email)
//Sua thong tin sinh vien
std['fullname'] = "TRAN VAN A"
std['age'] = 20
console.log(std)
std.fullname = "TRAN VAN AA"
std.age = 22
console.log(std)
//Nhan xet: doi tuong std -> gom 3 thuoc tinh: fullname, age, email
//Bai toan -> them cac thuoc tinh khac: address, gender vao std thi lam the
std.address = 'Ha Noi'
std.gender = 'Nam'
console.log(std)
//Phan 4: Khai bao mang object
var stdList = []
var std = {
"fullname": "Tran Van A",
"age": 22,
"email": "a@gmail.com"
}
stdList.push(std)
console.log(stdList)
std = {
"fullname": "Tran Van B",
"age": 25,
"email": "b@gmail.com"
}
stdList.push(std)
console.log(stdList)
//tat ca chuc nang: them, sua, xoa, chen -> hoat dong dung t/c array -> da de cap o tren.
//Khai bao mang gom 3 sinh vien san ngay tu dau
var studentList = [
{
"fullname": "Tran Van A",
"age": 22,
"email": "a@gmail.com"
}, {
"fullname": "Tran Van B",
"age": 21,
"email": "b@gmail.com"
}, {
"fullname": "Tran Van C",
"age": 26,
"email": "c@gmail.com"
}
]
console.log(studentList)
</script>
<table border="1" cellpadding="5">
<thead>
<tr>
<th>STT</th>
<th>Ho Ten</th>
<th>Tuoi</th>
<th>Email</th>
</tr>
</thead>
<tbody>
<script type="text/javascript">
// x = 5
// document.write('<br/>x = ' + x)
// document.write(`<br/>x = ${x}`)
for (var i = 0; i < studentList.length; i++) {
document.write(`<tr>
<td>${i + 1}</td>
<td>${studentList[i].fullname}</td>
<td>${studentList[i].age}</td>
<td>${studentList[i].email}</td>
</tr>`)
}
</script>
</tbody>
</table>
</body>
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