Java学习的第三十八天

例3.4.

package bgio;
public class cjava {
public static void main(String[]args) {
int i=1;
int sum=0;
while(i<=100) {
    sum=sum+i;
    i++;
}
System.out.println("sum"+sum);
}
}

 例3.5

package bgio;
public class cjava {
public static void main(String[]args) {
int i=1;
int sum=0;
do {
    sum=sum+i;
    i++;
}while(i<=100);
System.out.println("sum"+sum);
}
}

 例3.6

package bgio;
public class cjava {
public static void main(String[]args) {
int s=1;
double n=1,t=1,pi=0;
while((Math.abs(t))>(1e-7))
        {
    pi=pi+t;
    n=n+2;
    s=-s;
    t=s/n;
        }
pi=pi*4;
System.out.println("pi="+pi);
}
}

 2.数学方法不太知道.

3.明天继续写例题