删除元素后重新排列数组

Question

In my application I'm having a list of items which will be pushed into an array when checking that and will be removed from the array when unchecked. Here is the code

          if (data.selectedInsertion === true) {
                order.push(data);
            }
            else if (data.selectedInsertion === false) {
                angular.forEach(order, function (value,key) {
                    if (value == data) {
                        delete order[key];
                    }
                })
            }

The problem is when the 5th element in the array is deleted, the array will be missing that key forever and so when I display it in the template using angularjs it will show a blank row in the place or the missing 5th element.How can I re arrange the array after removing the element.

Answer 1

if (data.selectedInsertion === true) {
    order.push(data);
}
else if (data.selectedInsertion === false) {
    order.splice(order.index(data),1);
}

Answer 2

Assuming that all the values in your array are unique, you can do it like this:

if(data.selectedInsertion) {
  order.push(data);
} else {
  order.splice(order.indexOf(data),1)
}

Array.splice removes elements from an array. Check this link for more information: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice

If data is not unique, only the first occurence in the array is removed.

Also, you can leave out the explicit checks for true and false , especially since it seems to be a boolean value.

Answer 3

Remember one never use delete to remove elements from an array. As it will remove the element leaving undefined under it's key. Thus, you can splice it or filter it out.

Filter it out:

if (data.selectedInsertion === true) {
    order.push(data);
}
else if (data.selectedInsertion === false) {
    order = order.filter(function(v){
    return v !== data;
    });
}

Splice it

if (data.selectedInsertion === true) {
    order.push(data);
}
else if (data.selectedInsertion === false) {
    order.splice(order.indexOf(data),1);
}

delete is used to remove a property from an object.