there are different ways of adding the numbers in java. the numbers to be added can be given as input at runtime or can be put directly inside the program. however, it is difficult to add numbers in this way if the list of numbers is too big. sometimes, the data to be added is given in an excel spreadsheet/ google sheet. so, the easy way is to save the excel spreadsheet /google sheet into a file with extension csv (comma separated values) and then csv file’s column can be selected for adding up the values together using java program. in this article, both the approaches of summations of numbers are specified.
多种方法
对于通过Java程序进行数字求和，使用以下两种方法。
Approach 1: Getting the numbers from the user at runtime.
方法2：使用Java通过csv文件添加数字。
Let’s see the programs along with the output one by one.
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方法一：在运行时从用户获取数字
In this approach, the scanner class will be used to take the user input and write the necessary code to print the computed result.
算法
Step 1 − Ask the user how many numbers the user want to add.
Step 2 − Ask the user the numbers to be added.
第三步 - 添加输入的数字。
步骤 4 - 显示数字的总和。
示例（方法1）
import java.util.Scanner;
public class newarr {
public static void main(String[] args) {
int nn;
// Scanner is used to take input from the user
Scanner scnn=new Scanner(System.in);
System.out.print("Enter the number of items you want to add: ");
//get the input
nn=scnn.nextInt();
int[] arrayofNum = new int[10];
System.out.println("Enter the numbers to be added: ");
for(int n=0; n<nn; n++){
arrayofNum[n]=scnn.nextInt();
}
int summ = 0;
// adding Numbers
for (int m = 0; m < arrayofNum.length; m++)
summ += arrayofNum[m];
// printing the sum
System.out.println("Sum of given array is "+ summ);
}
}
Output
Enter the number of items you want to add: 10 Enter the numbers to be added: 200 320 56 67 6768768 5454 67667 7878 78 99 Sum of given array is 6850587
Approach-2: Adding the numbers through CSV file using Java
In this approach, Excel spreadsheet are used. Then as per the algorithm, the program code would fetch the numbers which are presented in the sheet and the addition of the numbers would be displayed in output.
算法
步骤 1 − 将Excel电子表格/ Google表格保存为CSV格式。
第二步 - 逐行读取CSV文件。
Step 3 − Skip the header lines.
第四步 − 选择要添加数据的列号。
第五步 - 将字符串类型的数据转换为数值形式。
步骤 6 − 添加指定列的数字。
Step 7 − Print the result.
CSV file Content
Year,2022 Months,Icecream sales (Rs) Jan,100034 Feb,245767 Mar,391500 Apr,537233 May,682966 Jun,1028699 Jul,974432 Aug,890165 Sep,265898 Oct,141163 Nov,135736 Dec,103097
例子（方法2）
import java.io.File;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.util.*;
public class numbers {
public static void main(String[] args) throws Exception {
// specify the header lines in the csv file to skip
int headerlines=2;
int sum=0;
// Read the csv file
File file = new File("icecream_sales.csv");
// Read all lines
List<String> lines = Files.readAllLines(file.toPath(),StandardCharsets.UTF_8);
// variable to hold int values after conversion
int a;
//current row number
int rowcount=1;
for (String line : lines) {
//skip the number of header lines in csv file
if (rowcount<=headerlines){
rowcount=rowcount+1;
continue;
}
String[] array = line.split(",", -1);
//read the numbers from the second column after skipping the header lines
a= Integer.parseInt(array[1]);
System.out.println("Icecream Sales (in INR) for the month of "+ array[0] + " is "+ a);
//Adding the numbers from the second column of CSV file
sum =sum +a;
}
// printing the sum
System.out.println("Total sum (in INR) for icecream sale in the given year is :" + sum);
}
}
Output
Icecream Sales (in INR) for the month of Jan is 100034 Icecream Sales (in INR) for the month of Feb is 245767 Icecream Sales (in INR) for the month of Mar is 391500 Icecream Sales (in INR) for the month of Apr is 537233 Icecream Sales (in INR) for the month of May is 682966 Icecream Sales (in INR) for the month of Jun is 1028699 Icecream Sales (in INR) for the month of Jul is 974432 Icecream Sales (in INR) for the month of Aug is 890165 Icecream Sales (in INR) for the month of Sep is 265898 Icecream Sales (in INR) for the month of Oct is 141163 Icecream Sales (in INR) for the month of Nov is 135736 Icecream Sales (in INR) for the month of Dec is 103097 Total sum (in INR) for icecream sale in the given year is :5496690
Conclusion
In this article, two different programs are given to add the numbers using the java code. In the first approach, the numbers are given by the user at run time and in the second approach, the numbers are taken from a column of a CSV file for summation.
