Javascript 删除对象时布尔值数组是否未定义?
我有一些拖放对象的数组,这里:Javascript 删除对象时布尔值数组是否未定义?,javascript,jquery-ui-droppable,Javascript,Jquery Ui Droppable,我有一些拖放对象的数组,这里: var elmDragObj = ["#ob01","#ob02","#ob03","#ob04","#ob05","#ob06","#ob07","#ob08","#ob09","#ob10","#ob11","#ob12","#ob13","#ob14","#ob15","#ob16","#ob17","#ob18","#ob19","#ob20"]; var elmDropObj = ["#va_kb_a","#va_ks_a","#va_kk_a","#
var elmDragObj = ["#ob01","#ob02","#ob03","#ob04","#ob05","#ob06","#ob07","#ob08","#ob09","#ob10","#ob11","#ob12","#ob13","#ob14","#ob15","#ob16","#ob17","#ob18","#ob19","#ob20"];
var elmDropObj = ["#va_kb_a","#va_ks_a","#va_kk_a","#dk_kb_a","#dk_kb_b","#dk_ks_a","#pr_kb_a","#rv_kb_a","#rv_kb_b","#rv_kb_c","#pr_ks_a","#rv_ks_a","#rv_ks_b","#rv_ks_c","#vl_kb_a","#vl_ks_a","#vl_kk_a","#vk_kb_a","#vk_ks_a","#vk_kk_a"];
我有一个布尔数组,当所有对象都放在它的位置上时,我要检查它,这里:
var elmBool = [false,false,false,false,false,false,false,false,false,false,false,false,false,false,false,false,false,false,false,false];
当我想检查布尔值时,它是未定义的,脚本如下:
for(var j=0; j<elmDragObj.length; j++){
$(elmDragObj[j]).draggable({revert:"invalid"});
$(elmDropObj[j]).droppable({
accept: elmDragObj[j],
drop: function( event, ui ) {
alert(elmBool[j]);
}
});
}
for(var j=0;j问题是变量j在调用函数时无效。您已经运行了循环,并且j无效,它已经增加到数组的末尾。这是因为在
alert(elmBool[j]);
…运行时,j
现在超出了数组的范围(它将等于elmDragObj.length
)
最简单的解决方案是简单地使用$。each()
:
如果您真的想为
循环使用,可以这样做,但您需要在闭包中“锁定”j
的值:
for(var j=0; j<elmDragObj.length; j++){
$(elmDragObj[j]).draggable({revert:"invalid"});
$(elmDropObj[j]).droppable({
accept: elmDragObj[j],
drop: (function() {
var index = j;
return function(event, ui) {
alert(elmBool[index]);
};
})()
});
}
for(var j=0;ja在drop
处理程序触发时,它将尝试使用j
在for()结尾处结束的值循环,而不是定义drop时的值。例如,您没有在循环的某个特定点嵌入j。elmBool是在for循环之前声明的吗?另外,如果您只回显j,会发生什么情况。那么..如何获取布尔值?仅获取可拖放对象的名称。。
for(var j=0; j<elmDragObj.length; j++){
$(elmDragObj[j]).draggable({revert:"invalid"});
$(elmDropObj[j]).droppable({
accept: elmDragObj[j],
drop: (function() {
var index = j;
return function(event, ui) {
alert(elmBool[index]);
};
})()
});
}