import java.util.List;
import java.util.ArrayList;
import java.util.Set;
import java.util.HashSet;
public class Code { public static void main(String [] args) {
testA();
System.out.println("===========================");
testB();
System.out.println("===========================");
testC();
} //去掉数组中重复的值
public static void testA() {
String [] str = {"Java", "C++", "Php", "C#", "Python", "C++", "Java"};
for (String elementA:str ) {
System.out.print(elementA + " ");
}
List<String> list = new ArrayList<String>();
for (int i=0; i<str.length; i++) {
if(!list.contains(str[i])) {
list.add(str[i]);
}
}
String[] newStr = list.toArray(new String[1]); //返回一个包含所有对象的指定类型的数组
for (String elementB:newStr ) {
System.out.print(elementB + " ");
}
System.out.println();
} //删除数组中其中一个元素
public static void testB() {
String [] str = {"Java", "C++", "Php", "C#", "Python"};//删除php
List<String> list = new ArrayList<String>();
for (int i=0; i<str.length; i++) {
list.add(str[i]);
}
list.remove(2); //list.remove("Php")
String[] newStr = list.toArray(new String[1]); //返回一个包含所有对象的指定类型的数组
} //在数组中增加一个元素
public static void testC() {
String [] str = {"Java", "C++", "Php", "C#", "Python"};//增加ruby
List<String> list = new ArrayList<String>();
for (int i=0; i<str.length; i++) {
list.add(str[i]);
}
list.add(2, "ruby");
String[] newStr = list.toArray(new String[1]); //返回一个包含所有对象的指定类型的数组
}
}
定义一个类型的二维数组 String[][] a;
定义一维数组长度 a = new String[i][];
定义二维数组长度 a[i] = new String[j]
例子：将一个字符串的内容分隔，并且放入一个二维数组中
public class TestToString {
public static void main(String[] args) {
String s = "0,1;3,6,4;7,1";
String[] a = s.split(";");
double[][] d;
d = new double[a.length][];
for(int i=0; i<a.length; i++){
String[] s_num = a[i].split(",");
for(int j=0; j<s_num.length; j++){
d[i] = new double[s_num.length];
d[i][j] = Double.parseDouble(s_num[j]);
System.out.println("d[" + i + "][" + j +"] = " + d[i][j]);
}
}
}