<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<script type="text/javascript">
test();
function test(){
alert(‘this is a test‘);
} 函数名称严格区分大小写
function TEST(){
alert("hello king");
}
TEST();
test();
function test(){
alert(‘hello nana‘); 函数名称重复会产生覆盖
}
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>
原文：https://www.cnblogs.com/d-z-j-boke/p/9543600.html