#include <stdio.h>
 
void cat_data( int *data1, const int *data2, int len2 ){
    int i;
    for(i = 0; i < len2; i++){
        data1[2 + i] = data2[i];
    }
}
 
int main(void){
    int data1[7] = {1, 2};         
    int data2[5] = {3, 4, 5, 6, 7};
 
 
    int len2 = sizeof(data2) / sizeof(data2[0]);
 
    cat_data(data1, data2, len2);
 
    for(int i = 0; i < 7; i++){
        printf("data1[%d] = %d\n", i, data1[i]);
    }
 
    return 0;
}
 

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