아는만큼 보여요

var win = window.open(canvas.toDataURL('image/png'));//정상적으로 열리지 않는다.

var win = window.open();

win.document.write("<img src='"+canvas.toDataURL('image/png')+"'/>");//정상적으로 열림

var n = [12, -8, 40, -22, 8, 27, 89, 62, -90]

function compNumber(a, b){

return a - b;

}

console.log(n.sort(compNumber));

console.log(!!0); //false

console.log(!!1); //true

console.log(!!'string'); //true

console.log(!!''); //false

console.log(!!true); //true

console.log(!!false); //false

console.log(!!null); //false

console.log(!!undefined) //false

var arr = [1, 2, 3, 4, 5];

arr.splice(2,1); //2번째 요소를 시작점으로 1개 원소 삭제

console.log(arr); //[1,2,4,5]

console.log(arr.length); //4

var empty;

console.log(empty); //undefined

console.log(typeof empty); //undefined

var _null = null;

console.log(_null); //object

console.log(typeof _null === null); //false

console.log(_null === null); //true

var string='UPPER lower';

string=string.toUpperCase();

console.log(string); //UPPER LOWER

string=string.toLowerCase();

console.log(string); //upper lower

var offsetX = (event.offsetX || event.layerX);