全選全不選(優化)
阿新 • • 發佈:2022-03-28
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title></title> <script type="text/javascript"> window.onload = function() { var sg = document.getElementsByName("sg"); function checked(num) {for (let i = 0; i < sg.length; i++) { switch (num) { case 1: sg[i].checked = true; break; case 2: sg[i].checked = false;break; case 3: sg[i].checked = !sg[i].checked; } } } document.getElementsByName("All")[0].onclick = function() { checked(1); } document.getElementsByName("noAll")[0].onclick = function() { checked(2) } document.getElementsByName("noresAll")[0].onclick = function() { checked(3) } } </script> </head> <body> 蘋果:<input type="checkbox" name="sg" value="蘋果"> 香蕉:<input type="checkbox" name="sg" value="香蕉"> 梨子:<input type="checkbox" name="sg" value="梨子"> <br> <input type="button" name="All" value="全選"> <input type="button" name="noAll" value="全不選"> <input type="button" name="noresAll" value="反選"> </body> </html>