<!DOCTYPE html
>
<
html
lang=
"en"
>
<
head
>
<
meta
charset=
"UTF-8"
>
<
meta
name=
"viewport"
content=
"width=device-width, initial-scale=1.0"
>
<
meta
http-equiv=
"X-UA-Compatible"
content=
"ie=edge"
>
<
title
>Document
</
title
>
</
head
>
<
body
>
</
body
>
<
script
>
var
a =
"abc";
var
b =
"EFG";
// 将字符串字母大写转化成小写的方法
var
c =
a.
toUpperCase();
console.
log(
c);
//ABC
// 将字符串字母小写转换成大写的方法
var
d =
b.
toLowerCase();
console.
log(
d);
//efg
<
/
script
>
</
html
>