[JSベース]変数、データ型、関数、条件文、繰返し文

let a_list = ['minsu','haneul','jaewan']
undefined
a_list[0]
"minsu"
a_list.push('yoonhee')
4
a_list[3]
"yoonhee"
a_list
(4) ["minsu", "haneul", "jaewan", "yoonhee"]

let a_dict = {'name':'jamie', 'age':32}
undefined
a_dict['name']
"jamie"
a_dict['age']
32
a_dict['nationality'] = 'USA'
"USA"
a_dict
{name: "jamie", age: 32, nationality: "USA"}

#딕셔너리와 리스트는 서로의 요소로 쓰일 수도있다.
a_dict['friends'] = a_list
(4) ["minsu", "haneul", "jaewan", "yoonhee"]
a_dict
{name: "jamie", age: 32, nationality: "USA", friends: Array(4)}
a_dict['friends'][2]
"jaewan"

#부르면 정해진 동작을 하는것이 함수
function sum(num1, num2){
    return num1+num2
}
undefined
let result = sum(2,3)
undefined
result
5

function mysum(num1, num2){
    alert('Hello World!')
    return num1+num2
}
undefined
let result2 = mysum(2,3)
undefined
result2
5

let age = 24
undefined
if (age>20) {
    console.log('adult')
} else {
    console.log('kid')
}
VM2471:2 adult
undefined


let sex='male'
if (age > 20 && sex =='male'){
    console.log('male adult')
} else {
    console.log('kid')
}
male adult
undefined