<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<input type="button" value="我要计算">
<script>
// document.querySelector('input')[0].click=window.open('A.html','_blank','width=400,height=100,left=200,top=200,scrollbars=no,menubar=no')
var btn=document.querySelector('input')[0];
btn.addEventListenner('click',function(){
window.open('A.html','_blank','width=400,height=100,left=200,top=200,scrollbars=no,menubar=no')
})
</script>
</body>
</html>
document.querySelector('input')不需要在后面加[0]。