C 警告：数组初始化程序中的多余元素和程序未提供预期的 output

Question

I have below code. My program is objectives to count yearly total rainfall by year 2010-2014. I have declared two dimension array. you can see in code snippet.However I have added 12 month for each year but compiler gives below warning. Please help to fix warning and incorrect output

1. Compiler gives warning

multi_dimension_array.c:14:54: warning: excess elements in array initializer [-Wexcess-initializers]
        {4.3,4.3,4,3,3.0,2.0,1.2,0.2,0.2,0.4,2.4,3.5,6.6},

second issue is that it does not gives expected output.

/*
Program name: multi_dimension_array.c
Date: 2022-01-29-23:50:41
*/
#include<stdio.h>
#define MONTHS 12   // number of months in a year
#define YEARS 5     // number of years of data
int main()
{
    float sub_total = 0;
    float total = 0;
    
    //initializing rainfall data for 2010-2014
    float rain[YEARS][MONTHS]=
    {
        {4.3,4.3,4,3,3.0,2.0,1.2,0.2,0.2,0.4,2.4,3.5,6.6}, //warning at this line no.14
        {8.5,8.2,1.2,1.6,2.4,0.0,5.2,0.9,0.3,0.9,1.4,7.3},
        {9.1,8.5,6.7,4.3,2.1,0.8,0.2,0.2,1.1,2.3,6.1,8.4},
        {7.2,9.9,8.4,3.3,1.2,0.8,0.4,0.0,0.6,1.7,4.3,6.2},
        {7.6,5.6,3.8,2.8,3.8,0.2,0.0,0.0,0.0,1.3,2.6,5.2}
    };

    for(int i= 0;i<YEARS;i++)
    {
        for(int j =0; j<MONTHS;j++)
            sub_total += rain[i][j];
        
        printf("%d %f \n", (2010+i),sub_total);
        total += sub_total;  // total for all years

    }
    return 0;
}

Actual Program output:

J2V1-MacBook-Air~  # cd "/Users/J2V1/Desktop/coding/c_code/mix/" && gcc multi_dimension_array.c -o multi_dimension_array && "/Users/J2V1/Desktop/coding/c_code/mix/"multi_dimension_array
multi_dimension_array.c:14:54: warning: excess elements in array initializer [-Wexcess-initializers]
        {4.3,4.3,4,3,3.0,2.0,1.2,0.2,0.2,0.4,2.4,3.5,6.6},
                                                     ^~~
1 warning generated.
2010 28.500002 
2011 66.400009 
2012 116.200005 
2013 160.199997 
2014 193.100021 

Expected output

2010 32.4 
2011 37.9
2012 49.8 
2013 44.0 
2014 32.9 

Answer 1

This array declaration

float rain[YEARS][MONTHS]= ...

is equivalent vto

float rain[5][12]= ...

That is each element of the array has 12 sub-elements. But you supplied 13 initializers

{4.3,4.3,4,3,3.0,2.0,1.2,0.2,0.2,0.4,2.4,3.5,6.6},
         ^^^

It seems there is a typo in the initializer list and you mean

{4.3,4.3,4.3,3.0,2.0,1.2,0.2,0.2,0.4,2.4,3.5,6.6},
         ^^^

Also in this nested for loops

for(int i= 0;i<YEARS;i++)
{
    for(int j =0; j<MONTHS;j++)
        sub_total += rain[i][j];
    
    printf("%d %f \n", (2010+i),sub_total);
    total += sub_total;  // total for all years

}

you need reassign sub_total in the outer loop. SO the loops should look like

for(int i= 0;i<YEARS;i++)
{
    sub_total = 0.0f;
    for(int j =0; j<MONTHS;j++)
        sub_total += rain[i][j];
    
    printf("%d %f \n", (2010+i),sub_total);
    total += sub_total;  // total for all years

}  

Pay attention to that the value of the variable total in fact is not used. Maybe you need to output it in the program.

Answer 2

The warning is due to {4.3,4.3,4,3,3.0,2.0,1.2,0.2,0.2,0.4,2.4,3.5,6.6} having 13 elements instead of the intended 12 elements. the 3rd element should be 4.3 instead of 4,3.

Edit:As mentioned by @Jonathan using spaces after each element will help finding such mistakes easier.

Answer 3

Your first row contains 13 column which is supposed to be 12.