console
$(function(){
function btn(ind){
var num;
switch(ind){
case 1:
num = 1;
break;
case 2:
num = 2;
break;
case 3:
num = 3;
break;
case 4:
num = 4;
break;
}
alert(num);
}
$(".btn1").on('click',function(){
btn(1);
});
$(".btn2").on('click',function(){
btn(2);
});this
$(".btn3").on('click',function(){
btn(3);
});this
$(".btn4").on('click',function(){
btn(4);
});
})
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<title>Document</title>
</head>
<body>
<input type="button" value="btn1" class="btn1" />
<input type="button" value="btn2" class="btn2" />
<input type="button" value="btn3" class="btn3" />
<input type="button" value="btn4" class="btn4" />
</body>
</html>