5.if语句


<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html;charset=UTF-8"> <title>js基础-分支结构-if语句</title> <style type="text/css"> </style> <script type="text/javascript"> function gosum(){ var x=59; var y=70; if (x>y){ document.getElementById("sum").innerHTML="x比较大"; }else if(x==y){ document.getElementById("sum").innerHTML="x与y相等"; }else{ document.getElementById("sum").innerHTML="x比较小"; } /*结果输出在页面中 document为文档节点 getElementById为方法,根据id获得节点 innerHTML在节点写入内容。 */ } </script> </head> <body> <span>5.if语句</span><hr> <span id="sum"></span><br> <button id="go" onclick="gosum()">运行</button> <hr> </body> </html>