<!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>
<
script>
var j
=
0;
var i
=
0;
var m
=
0;
window.
onload
=
function(){
setInterval(
'change()',
10);
}
function
change(){
i
++;
if(i
===
100){
j
++;
i
=
0;
}
if(j
===
60){
m
++;
j
=
0;
}
document.
getElementById(
'p1').innerHTML
=m
+
'分钟'
+j
+
'.'
+i
+
'秒';
}
function
restart(){
i
=
0;j
=
0;m
=
0;
document.
getElementById(
'p1').innerHTML
=m
+
'分钟'
+j
+
'.'
+i
+
'秒';
}
function
addFive(){
j
+=
5;
document.
getElementById(
'p1').innerHTML
=m
+
'分钟'
+j
+
'.'
+i
+
'秒';
}
</
script>
<
p
id=
"p1">0</
p>
<
button
onclick=
"restart()">重置</
button>
<
button
onclick=
"addFive()">加五秒</
button>
</
body>
</
html>