Convert multiple Integers into a single string

Question

I have a function that pulls the X,Y,Z co-ords of an accelerometer and stores them in 3 individual integers.

I want to send these via a wireless chip on my microcontroller, but the transmit function takes a string parameter.

So I want to combine the integers into one string and then send this string.

I have:

    Int xData;
    Int yData;
    Int zData;

char totalData[64]

But would like to combine them into a string that is something like this:

("X:" + xData + " Y:" + yData + " Z: "xData)

Answer 1

Use sprintf. It works like printf, but the output is put into a char array instead of being sento to stdout:

sprintf(totalData, "X:%d: Y:%d: Z:%d", xData, yData, zData);

Answer 2

Good to prevent buffer overruns. Use snprintf() and check results.

int n = snprintf(totalData, sizeof totalData, "X:%d Y:%d Z: %d", xData, yData, zData);
if (n >= 0 && n < sizeof totalData) {
  Success_SendIt(totalData);
}

---

Another method that addresses all but the the most pedantic, conservatively "right-size" the buffer and does not use the magic number 64.

// Longest string length of an int
#include <stdlib.h>
#define INT_STR_LEN (sizeof(int)*CHAR_BIT/3 + 2)

int xData;
int yData;
int zData;
const char format[] =  "X:%d Y:%d Z: %d";
char totalData[INT_STR_LEN*3 + sizeof(format) + 1];

sprintf(totalData, format, xData, yData, zData);
SendIt(totalData);

Answer 3

Write like this:

#include <stdio.h>


int main()
{
    int x, y,z;
    x=1, y=2, z=3;
    char w[6];
    sprintf(w, "%d%d%d", x,y,z);
    printf(w);

}

change w[i] size upon your need.