Java 语法 索引 ----- 数组(Arrays)

数组声明，分配， 赋值

int y[] = new int[3];

y[0] = 1;
y[1] = 2;
y[2] = 3;

int[] x = new int[] {1,2,3};
int[] x = {1,2,3};

 

二维数组

String[][] x = {{"00","01"},{"10","11"}};
String[][] y = new String[2][2];

y[0][0] = "00";
y[0][1] = "01";
y[1][0] = "10";
y[1][1] = "11";

 

Arraylist

java.util.ArrayList a = new java.util.ArrayList();

a.add("Hi"); // add an element
a.set(0, "Hello"); // change first element
a.remove(0); // remove first element

a.add("Hello World");
String s = (String)a.get(0); // Hello World