函数:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
</body>
</html>
<script>
function hello(){
alert('hello world!');
}
hello(); //方法调用
var hello1 = function(){
alert("hello 你好！");
}
hello1(); // 变量名+（）来调用
//js声明方法时，不需要给参数设置类型
function sum(num1, num2, num3){
alert(num1 + num2 + num3);
}
sum(10,20,30);
//定义带返回值的方法
function sum2(num1,num2,num3){
return num1 + num2 + num3; //返回计算结果
}
var result = sum2(1,2,3); //定义变量接收计算结果
alert(result);
//定义无参方法，使用arguments数组获取传入的参数
function max(){
var max = 0;
for(var i =0; i < arguments.length; i++){
//通过打擂的方式求最大值
if(max < arguments[i]){
max = arguments[i];
}
}
return max;
}
alert(max(89,90,56,67,99,26,45));
var name1 = '张三'; //全局变量
if(true){
alert(name1);
}
function getName(){
var name2 = '李四'; // 局部变量，为了函数失效，不能用了
alert('getName = ' + name1);
alert(name2);
}
getName(); //将会报错，没有name2
alert(name2);
</script>
调色板:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
#content{
height: 400px;
}
#tiao{
text-align: center;
}
</style>
</head>
<body>
<div id="content"></div>
<div id="tiao">
红:<input type="range" min="0" max="255" step="3" id="red" onchange="makeColor()"/>
绿：<input type="range" min="0" max="255" step="3" id="green" onchange="makeColor()"/>
蓝：<input type="range" min="0" max="255" step="3" id="blue" onchange="makeColor()"/>
</div>
</body>
</html>
<script>
function makeColor(){
var red = document.getElementById("red");
var green = document.getElementById("green");
var blue = document.getElementById("blue");
var r = parseInt(red.value);
var g = parseInt(green.value);
var b = parseInt(blue.value);
var content = document.getElementById("content");
content.style.backgroundColor = 'rgb(' + r + "," + g + "," + b + ")";
}
</script>
