<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<script type="text/javascript">
// test();
function test(){
alert('this is a test');
}
//test();
//函数名称严格区分大小写
function TEST(){
alert("hello king");
}
// TEST();
//函数名称重复会产生覆盖
//test();
function test(){
alert('hello nana');
}
// test();
function test1(){
alert('this is test1 function');
}
//alert(test1());
function test2(){
// return null;
// return undefined;
// return;
// return true;
// return 'this is king';
// return 1.2;
alert('this is a test');
// return 1;
}
//alert(typeof (alert('this is a test')));
function calc(num1,num2){
return num1+num2;
}
// alert(calc(1,2));
// alert(window.calc(3,5));
// alert(calc(1,2,3,4,5,6));
function calc1(num1=1,num2=2){
return num1+num2;
}
function calc1(num1,num2){
num1=num1||1;
num2=num2||2;
return num1+num2;
}
alert(calc1());
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<script type="text/javascript">
//实现默认参数的形式
function calc4(x,y){
x=x||0;
y=y||0;
return x+y;
}
function calc4(x,y){
if(x===undefined){
x=0;
}
y=y===undefined?0:y;
return x+y;
}
//alert(calc4());
//alert(calc(1,3,4)); //控制着对象的长度
function calc(x,y){
//return arguments;
// alert(arguments[0]);
// alert(arguments.length);
x=arguments[0]?arguments[0]:0;
y=arguments[1]?arguments[1]:0;
return x+y;
}
//alert(calc());
//alert(calc(1,2));
//可变参数形式的函数
function test(){
var paramsNum=arguments.length;//得到传入参数的个数
var sum=0;
for(var i=0;i<paramsNum;++i){
sum+=arguments[i];
}
return sum;
}
//alert(test(1,2,3,4,5,6));
function test1(){
var paramsNum=arguments.length;
var max=0;
for(var i=0;i<=paramsNum-1;i++){
if(arguments[i]>max){
max=arguments[i];
}
}
return max;
}
alert(test1(123,3432,23456,445643));
</script>
</body>
</html>
