*/
console.log(1 === 1);
/*

*/

const c = "";
let l = '';
var v = `${c} 小于 ${l}`;

const el = document.querySelector("div.user-panel.main input[name='login']");
const matches = container.querySelectorAll("li[data-active='1']");

const fruits = [];
const arrayEmpty = new Array();

arraySparse.forEach((element) => {
  const count = animals.push("cows");
});

clothing.length

const o = new Object();
o.foo = 42;
const person = {};

const firstElement = array1.shift();

for (let i = 0; i < 9; i++) {
  str = str + i;
}

node.parentNode

console.log(typeof undeclaredVariable);

Dog.prototype.toString = function dogToString() {
  return `${this.name}`;
};

regex.test(str)

undefined

document.body.appendChild(p);

if ( true ) {
    result = "positive";
} else {
    result = "NOT positive";
}

const func2 = (x, y) => {
    return false;
}

async

const newDiv = document.createElement("div");
newDiv.textContent = "This text is different!";

my_element.addEventListener("click", () => {
    
});

mouseover

mouseleave

mouseout

switch (foo) {
  case -1:
    console.log("负 1");
    break;
  case 0:
    console.log(0);
  case 1:
    console.log(1);
    break; // 遇到 break，不会继续到 'case 2:'
  case 2:
    console.log(2);
    break;
  default:
    console.log("default");
}

/*