java - 如何将新元素添加到数组？(How to add new elements to an array?)

Question

I have the following code:

(我有以下代码：)

String[] where;
where.append(ContactsContract.Contacts.HAS_PHONE_NUMBER + "=1");
where.append(ContactsContract.Contacts.IN_VISIBLE_GROUP + "=1");

Those two appends are not compiling.

(这两个附录未编译。)

How would that work correctly?

(那将如何正常工作？)

  ask by Pentium10 translate from so

Answer 1

The size of an array can't be modified.

(数组的大小无法修改。)

If you want a bigger array you have to instantiate a new one.

(如果需要更大的数组，则必须实例化一个新数组。)

A better solution would be to use an ArrayList which can grow as you need it.

(更好的解决方案是使用ArrayList ，它可以根据需要增长。)

The method ArrayList.toArray( T[] a ) gives you back your array if you need it in this form.

(如果您需要这种形式的数组，则ArrayList.toArray( T[] a )将为您提供数组。)

List<String> where = new ArrayList<String>();
where.add( ContactsContract.Contacts.HAS_PHONE_NUMBER+"=1" );
where.add( ContactsContract.Contacts.IN_VISIBLE_GROUP+"=1" );

If you need to convert it to a simple array...

(如果需要将其转换为简单数组...)

String[] simpleArray = new String[ where.size() ];
where.toArray( simpleArray );

But most things you do with an array you can do with this ArrayList, too:

(但是，使用数组执行的大多数操作也可以使用此ArrayList执行：)

// iterate over the array
for( String oneItem : where ) {
    ...
}

// get specific items
where.get( 1 );