JavaScript『変数･定数･関数』

(var variable=10;)

var variable=10;

(let variable=20;)

let variable=20;

(const constant=30;)

const constant=30;

({var num=10; console.log(num);})

{var num=10; console.log(num);}

(let string='abc';)

let string='abc';

(let number=12;)

let number=12;

(let boolean=false;)

let boolean=false;

(const array=[];)

const array=[];

(const objectName={key:'value'}; console.log(objectName.key);)

const objectName={key:'value'}; console.log(objectName.key);

(const girl={name:'mari',age:15}; console.log(girl.name,girl.age);)

const girl={name:'mari',age:15}; console.log(girl.name,girl.age);

(calc(); function calc(){alert(100*100);})

calc(); function calc(){alert(100*100);}

(const circle=function(r){return r*r*3;}; const area=circle(10);console.log(area);)

const circle=function(r){return r*r*3;}; const area=circle(10);console.log(area);

(const arrow=(x,y)=>x*y; arrow(10,100);)

const arrow=(x,y)=>x*y; arrow(10,100);

(const Maru={area:function(r){return r*r*3;}} console.log(Maru.area(5));)

const Maru={area:function(r){return r*r*3;}} console.log(Maru.area(5));

(const array=[0,2,4]; console.log(array[2]);)

const array=[0,2,4]; console.log(array[2]);

(const User={name:'Bob', tel:'000-1234-5678'})

const User={name:'Bob', tel:'000-1234-5678'}

(console.log(User.name);)

console.log(User.name);

(console.log(User['name']);)

console.log(User['name']);

(class Prototype{} console.log(new Prototype());)

class Prototype{} console.log(new Prototype());

(const text=document.getElementById('text'); console.log(text.innerHTML);)

const text=document.getElementById('text'); console.log(text.innerHTML);