CODEWITHSUNDEEP
cfor-loopstructwhile-loopcompare
newb7777
newb7777

Reputation: 563

In c language, Embedded Application, how to compare members from an Array of structure

I have a Memory chip that has data read by an embedded system serially. The memory device has 10 locations with each location having the following information: customerID, NumOfParts, MFGName. Here is my version of C code I wrote for this.

IN C FILE "PartName.h"

    //"PartName.h"
    #ifndef PartName_H
    #define PartName_H 

    typedef UINT8 MFGName_Struct_t [10];

    typedef struct
    {
        UINT8 customerID;
        UINT8 NumOfParts;
        MFGName_Struct_t MFGName;
    }IDENT_Struct_t;

    typedef struct MFG_Struct_t
    {
        UINT8 <some other variable>;        
        UINT8 <some other variable>;
        IDENT_Struct_t Ident1;
        IDENT_Struct_t Ident2;
        IDENT_Struct_t Ident3;
        IDENT_Struct_t Ident4;
        IDENT_Struct_t Ident5;
        IDENT_Struct_t Ident6;
        IDENT_Struct_t Ident7;
        IDENT_Struct_t Ident8;
        IDENT_Struct_t Ident9;
        IDENT_Struct_t Ident10; 
    } MFG_Struct_t;

    #endif

IN C FILE "HighNum.c"

    //"HighNum.c"
    #include "PartName.h"
    static MFG_Struct_t  MFG; 
    UINT8 HighNum(void)
   {
     //UINT8 i;
       UINT8 highestNum = 0;
     //for (i = 0;(i < 10);i++) 

       if (MFG.Ident1.NumOfParts > MFG.Ident2.NumOfParts)
       {
           highestNum = MFG.Ident1.NumOfParts;
       }
       if (MFG.Ident2.NumOfParts > MFG.Ident3.NumOfParts)
       {
           highestNum = MFG.Ident2.NumOfParts;
       }
       if (MFG.Ident3.NumOfParts > MFG.Ident4.NumOfParts)
       {
           highestNum = MFG.Ident3.NumOfParts;
       }
       if (MFG.Ident4.NumOfParts > MFG.Ident5.NumOfParts)
       {
           highestNum = MFG.Ident4.NumOfParts;
       }
       <and so on>      
     return highestNum;
   }

How can this be done more efficient in C? using for statements or While statements? I thought about concatenating the number portion and cycling through the variables...

Upvotes: 0

Views: 67

Answers (3)

SGeorgiades
SGeorgiades

Reputation: 1821

You could redefine the structure to put the 10 "Ident" values in an array, then use a for-loop to test your values:

typedef struct MFG_Struct_t
{
    UINT8 <some other variable>;        
    UINT8 <some other variable>;
    IDENT_Struct_t Ident[10];
} MFG_Struct_t;
    :
    :
UINT8 HighNum(void) {
    UINT8 i, highestNum = 0;

    for (i = 0; i < 9; i++) {
        if (MFG.Ident[i].NumOfParts > MFG.Ident[i+1].NumOfParts) {
            highestNum = MFG.Ident[i].NumOfParts;
        }
    }
    return highestNum;
}

or, better yet... change the HighNum function to be more efficient, as follows:

UINT8 HighNum(void) {
    UINT8 i, highestNum = MFG.Ident[0].NumOfParts;

    for (i = 1; i < 10; i++) {
        if (MFG.Ident[i].NumOfParts > highestNum) {
            highestNum = MFG.Ident[i].NumOfParts;
        }
    }
    return highestNum;
}

Upvotes: 1

Jimmy
Jimmy

Reputation: 223

I hope the following code can help you:

typedef struct MFG_Struct_t
{
    UINT8 <some other variable>;        
    UINT8 <some other variable>;
    IDENT_Struct_t Idents[10];
} MFG_Struct_t;

typedef enum _Idents
{
    Ident1 = 0,
    Ident2,
    Ident3,
    Ident4,
    Ident5,
    Ident6,
    Ident7,
    Ident8,
    Ident9,
    Ident10,
} IdentType;


   if (MFG.Idents[Ident1].NumOfParts > MFG.Idents[Ident2].NumOfParts)
   {
       highestNum = MFG.Idents[Ident1].NumOfParts;
   }


// or
for (index = Ident1; index < Ident10; index ++)
{
    if (MFG.Idents[index].NumOfParts > MFG.Idents[index +1].NumOfParts)
    {
        //......
    }
}

Upvotes: 1

unalignedmemoryaccess
unalignedmemoryaccess

Reputation: 7441

If you modify your structure to this:

#define IDENT_SIZE         10
typedef struct MFG_Struct_t
{
    UINT8 <some other variable>;        
    UINT8 <some other variable>;
    IDENT_Struct_t Ident[IDENT_SIZE];
} MFG_Struct_t;

Then you can do this:

size_t i = 0;
for (i = 0; i < IDENT_SIZE; i++) {
     if (MFG.Ident[i].NumOfParts > highestNum) {
           highestNum = MFG.Ident[i].NumOfParts;
     }
}

Upvotes: 1

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