public static void main(String[] args)
{
int[] a = new int[3];
Scanner in = new Scanner(System.in);
String num = "";
for (int i = 0; i < a.length; i++) {
System.out.println("请输入数组第"+(i+1)+"个元素");
num = in.nextLine();
if (isNum(num)) {
a[i] = Integer.valueOf(num);
}else{
System.out.println("非数字,请重新输入");
i--;
}
}
System.out.println("请输入一个数字");
num = in.nextLine();
if (isNum(num)) {
for (int j = 0; j < a.length; j++) {
if (a[j] == Integer.valueOf(num)) {
System.out.println(true);
return;
}
}
System.out.println(false);
}else{
System.out.println(false);
}
}
public static boolean isNum(String str){
return str.matches("^[-+]?(([0-9]+)([.]([0-9]+))?|([.]([0-9]+))?)$");
}
运行结果: