JavaScript Math acos 属性 JavaScript Math abs 属性 javascript while 循环 JavaScript Math acos 属性 <html> <head> <title>JavaScript Math acos() Method</title> </head> <body> <script type = "text/javascript"> var value = Math.acos(-1); document.write("First Test Value : " + value ); var value = Math.acos(null); document.write("<br />Second Test Value : " + value ); var value = Math.acos(30); document.write("<br />Third Test Value : " + value ); var value = Math.acos("string"); document.write("<br />Fourth Test Value : " + value ); </script> </body> </html> JavaScript Math abs 属性 javascript while 循环