js实现checkbox全选和反选示例_基础知识

function selectAll(form) {
var obj = document.getElementsByName('selectall');
var cks = document.getElementsByTagName("input");
var ckslen = cks.length;
for(var i=0;i if(cks[i].type == 'checkbox') {
cks[i].checked = obj[0].checked;
}
}
}