<!DOCTYPE html>
<html><head lang="en">
<meta charset="UTF-8">
<title></title>
</head><body> <button id="btn1">调用第一种</button>
<button id="bnt2">调用第二种</button>
<button id="btn3">调用第三种</button>
<script>
var btn1=document.getElementById('btn1');
btn1.onclick=function(){
document.body.style.background=bg1()
};
var btn2=document.getElementById('bnt2');
btn2.onclick=function(){
document.body.style.background=bg2();
};
var btn3=document.getElementById('btn3');
btn3.onclick=function(){
document.body.style.background=bg3();
};
function bg1(){
return '#'+Math.floor(Math.random()*256).toString(10);
}
function bg2(){
return '#'+Math.floor(Math.random()*0xffffff).toString(16);
}
function bg3(){
var r=Math.floor(Math.random()*256);
var g=Math.floor(Math.random()*256);
var b=Math.floor(Math.random()*256);
return "rgb("+r+','+g+','+b+")";//所有方法的拼接都可以用ES6新特性`其他字符串{$变量名}`替换
}
</script>
</body></html>