下列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 static void main (String[] args) { String text = "An array is a data structure that stores a collection of "+"values of the same type.You access each individual value"+"through an integer index.For example,if a is an array"+"of integers,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"); } }