feat: add day 5

pull/593/head
hoangdev72 3 years ago
parent 1b771fb6d6
commit 4e58a20337

@ -0,0 +1,151 @@
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<script>
const countries = [
'Albania',
'Bolivia',
'Canada',
'Denmark',
'Ethiopia',
'Finland',
'Germany',
'Hungary',
'Ireland',
'Japan',
'Kenya'
]
const webTechs = [
'HTML',
'CSS',
'JavaScript',
'React',
'Redux',
'Node',
'MongoDB'
]
// Declare an empty array;
let emptyArr = new Array()
// Declare an array with more than 5 number of elements
let arrayOf5Elements = Array(1, 2, 3, 4, 5)
// Find the length of your array
console.log(arrayOf5Elements.length)
// Get the first item, the middle item and the last item of the array
console.log(arrayOf5Elements[0], arrayOf5Elements[parseInt(arrayOf5Elements.length/2)], arrayOf5Elements[arrayOf5Elements.length - 1])
// Declare an array called mixedDataTypes, put different data types in the array and find the length of the array. The array size should be greater than 5
let mixedDataTypes = [1, "hello", true, Array(), NaN]
console.log(mixedDataTypes.length)
// Declare an array variable name itCompanies and assign initial values Facebook, Google, Microsoft, Apple, IBM, Oracle and Amazon
let itCompanies = ["Facebook", "Google", "Microsoft", "Apple", "IBM", "Oracle", "Amazon"]
// Print the array using console.log()
console.log(itCompanies)
// Print the number of companies in the array
console.log(itCompanies.length)
// Print out each company
console.log(itCompanies.join(' '))
console.log(itCompanies.toString())
// Change each company name to uppercase one by one and print them out
console.log(itCompanies.map(e => e.toUpperCase()).toString())
// Print the array like as a sentence: Facebook, Google, Microsoft, Apple, IBM,Oracle and Amazon are big IT companies.
console.log(itCompanies.join(", "))
// Check if a certain company exists in the itCompanies array. If it exist return the company else return a company is not found
let cpn = "Facebook"
if(itCompanies.includes(cpn)){
console.log(`${cpn} exists`)
}else{
console.log(`${cpn} not exists`)
}
// Filter out companies which have more than one 'o' without the filter method
console.log(itCompanies.filter(e => e.includes("o")).toString())
// Sort the array using sort() method
console.log(itCompanies.sort().toString())
// Reverse the array using reverse() method
console.log(itCompanies.sort().reverse().toString())
// Slice out the first 3 companies from the array
console.log(itCompanies.slice(0, 3))
// Slice out the last 3 companies from the array
console.log(itCompanies.slice(-3))
// Slice out the middle IT company or companies from the array
console.log(itCompanies.slice(parseInt(itCompanies.length/2), parseInt(itCompanies.length/2) +1 ))
// Remove the first IT company from the array
console.log(itCompanies.splice(0, 1))
// Remove the middle IT company or companies from the array
console.log(itCompanies.splice(parseInt(itCompanies.length/2), 1))
// Remove the last IT company from the array
console.log(itCompanies.splice(-1))
// Remove all IT companies
console.log(itCompanies.splice())
// In the following shopping cart add, remove, edit items
const shoppingCart = ['Milk', 'Coffee', 'Tea', 'Honey']
console.log(shoppingCart.filter(e => e != 'Milk'))
console.log(shoppingCart.shift())
shoppingCart.unshift('Orange')
console.log(shoppingCart)
console.log(shoppingCart.filter(e => e != 'Honey'))
// modify Tea to 'Green Tea'
console.log(shoppingCart.map((e) => {
return e == 'Tea' ? 'Green Tea' : e
}))
// In countries array check if 'Ethiopia' exists in the array if it exists print 'ETHIOPIA'. If it does not exist add to the countries list.
countries.includes('ETHIOPIA') ? countries : countries.push('ETHIOPIA')
console.log(countries)
const frontEnd = ['HTML', 'CSS', 'JS', 'React', 'Redux']
const backEnd = ['Node','Express', 'MongoDB']
console.log(fullStack = frontEnd.concat(backEnd))
const ages = [19, 22, 19, 24, 20, 25, 26, 24, 25, 24]
// Sort the array and find the min and max age
console.log(ages.sort().slice(0, 1))
console.log(ages.sort().slice(-1))
// Find the median age(one middle item or two middle items divided by two)
console.log(ages.sort().slice(parseInt(ages.length / 2), parseInt(ages.length / 2) +1 ) / 2)
// Find the average age(all items divided by number of items)
console.log(parseInt(ages.reduce((previousValue, currentValue) => previousValue + currentValue , 0) / ages.length))
// Divide the countries array into two equal arrays if it is even. If countries array is not even , one more country for the first half.
countries.pop()
if (countries.length % 2 == 0){
console.log(countries.slice(0, countries.length / 2), countries.slice(countries.length / 2, countries.length))
}else{
console.log(countries.slice(0, (countries.length / 2) +1), countries.slice((countries.length / 2) + 1, countries.length))
}
</script>
</body>
</html>
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