一维数组:
三种定义方法:
1.String [] arr = new String[4];
2.String [] arr = new String[]{"a","b","c","d"};
注意这种写法->String [] arr = new String[4]{"a","b","c","d"}; 编译会不通过
3.String [] arr = {"a","b","c","d"};
ps:至于[]在变量名arr前还是后,这个写法没有固定的要求,但是最好按照书上的标准来。
二维数组:
int [][] a = new int[3][4]; //3行4列
int [][] a = new int[3][]; //定义时行数不可省略,列数可省略