js">var a="Hello World"
document.write(a) //在网页上输出:Hello World
js">var a="Hello World"
console.log(a) //在控制上输出:Hello World
js">var a="Hello World"
document.write(a) //在网页上输出:Hello World
js">var a="Hello World"
console.log(a) //在控制上输出:Hello World