int num = 999;
int count = 0;
for (int i = 1;i<=10;i++ ) {
count++;
num /= 10;
if (num>1){
continue;
}else break;
}
System.out.println("它是个"+count+"位的数");
这是等腰三角形，n为层数。字数太多放不下，我就不空行了
int n = 6;
int m = (1+n)*n/2-1;
for (int i = 1; i <= n ; i++ ){
for (int j =1; j<=m ;j++ ){
if ((j > m/2+1-i ) && (j <=m/2+i )) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
System.out.println();
}
public class practise {
public static void main(String[] args) {
int sum = 0;
int num = 2;
do {
if (num % 2 == 0){
sum+=num;
}
num++;
} while ( num<=50 );
System.out.println(" 50以内的偶数之和为：" + sum );
}
}
