11.10 Object-oriented programming experiment report java

1. Experiment 2 Cycle structure, selection structure
Topic:

1. Output the sum of all even numbers from 1 to 100.
2. Program to find the maximum of three numbers.
3. Write a program to convert percentile grades into four-point grades. If the value range of the grade is [0,60), then print out "Fail"; if the value range is [60,75), then print out "Pass"; if the value range is [75,90), Then the printout is "good"; if the value range is [90,100], the printout is "excellent". For other value ranges, "The result is invalid" is printed.
4. Programmatically seek (result: 0.688)
5. Use the formula to find the approximate value of π until the absolute value of the last term is less than 10-6.

4. Program source code (core) and experimental results

Question 1:

 int i=0;int sum=0
while (i<100){
    i++;
    if(i%2==1)
        continue;sum=sum+i;
}System.out.print(sum); 

Question 2:

int []a=new  int [3];
Scanner sc=new Scanner(System.in);
for(int i=0;i<3;i++){
    System.out.print("请输入第"+(i+1)+"个数：");
    a[i]=sc.nextInt();
}
if (a[0]>=a[1] && a[0]>=a[2]){
    System.out.print(a[0]);
}
else if(a[1]>=a[2]){
    System.out.print(a[1]);
}
else{
    System.out.print(a[2]);
}  

Question 3:

Scanner sc=new Scanner(System.in);
System.out.print("请输入成绩：");
float cj=sc.nextFloat();
if(cj>=0 && cj<60){
    System.out.print("不及格");
}
else if (cj>=60 && cj<75){
    System.out.print("及格");
}
else if (cj>=75 && cj<90){
    System.out.print("良好");
}
else if (cj>=90 && cj<=100){
    System.out.print("优秀");
}
else{
    System.out.print("该成绩不合法");
}    

Question 4:

double sum=0;
double a=0;
for (int i=1;i<=100;i++){
    a=Math.pow(-1,i+1);
    sum=sum+(a*(1.0/i));
}
System.out.print(String.format("%.3f",sum));  

Question 5:

double sum=0;
int i=1,f=-1;
while (1.0/i>=Math.pow(10,-6)){
    f=-f;
    sum=sum+f*(1.0/i);
    i=i+2;
}
System.out.print(4*sum);