源代码:
<!DOCTYPE html> <html> <head> <script> function getElements() { var x=document.getElementsByName("x"); alert(x.length); } </script> </head> <body> Cats: <input name="x" type="radio" value="Cats"> Dogs: <input name="x" type="radio" value="Dogs"> <input type="button" onclick="getElements()" value="How many elements named 'x'?"> </body> </html>
运行结果：