下面程序的功能是统计字符串中“array”的个数,在程序的空白处应填入的正确选项是 public class FindKeyWords{ public static void main(String[]args) { String text='An array is a data structur that stores a collection of' +'values of the same type. You access each indMdual value' +'through an integer index. For example,if a is an array' +'of inergers,then a[i]is the ith integer in the array.'; int arrayCount=0; int index=-1; String arrayStr='array' index=text.indexOf(arrayStr); while(index>=0) { ++arrayCount; index+=arrayStr.length(); index=text.indexOf(arrayStr,index); } System.out.println('the text contains'+arrayCount+'arrays'); } }