$("#all").on("click",function(){
var ids1 = [];//数组
var ids2 = '';//字符串
var checks=$("input[type='checkbox']")
checks.each(function(){
$(this).prop("checked",true);//批量选中
ids1.push($(this).val());
ids2 += (","+$(this).val());
})
console.log(ids1);
console.log(ids2.substring(1));
});