declaration inside function syntax

Question

I am writing in C, not C++ or C# How can open additional array inside a function and put 0 in all its elements in one line only?

at the moment i have errors

Error 1 error C2065: 'new' : undeclared identifier

Error 3 error C2143: syntax error : missing ';' before 'type'

Error 4 error C2143: syntax error : missing ';' before '['

all errors at the same place - at the declaration of the new array

void dup(int a[], int n)
{
    int i;
    int *t = new int[n]; 

    for(i=0; i<=n; i++)
        t[i] = 0;

    for(i=0;i<n;i++)
        t[a[i]]++;
}

cnicutar · Accepted Answer · 2012-01-04 11:09:38Z

4

Try using calloc in stdlib.h:

int *t = calloc(n, sizeof *t);
if (!t) {
    perror("calloc");
    return;
}

answered Jan 4, 2012 at 11:09

cnicutar

184k26 gold badges378 silver badges398 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Dunes · Accepted Answer · 2012-01-05 10:15:02Z

3

new is a keyword specific to C++ and C#, and cannot be used in C.

Memory on the heap in C is primarily allocated via the function malloc and freed using the function free.

calloc is a version of malloc that also zeroes the memory before returning.

calloc take two arguments, the number of array elements and the size of each array element.

eg.

int i = 10;
int* p = calloc(i,sizeof(int));

http://www.cplusplus.com/reference/clibrary/cstdlib/calloc/

edited Jan 5, 2012 at 10:15

answered Jan 4, 2012 at 11:09

Dunes

42.1k7 gold badges86 silver badges107 bronze badges

2 Comments

Keith Thompson Over a year ago

No, in C you shouldn't cast the result of malloc or calloc.

Dunes Over a year ago

@KeithThompson Thanks. Never realised you didn't have to cast void pointers.

Pubby · Accepted Answer · 2012-01-04 11:10:18Z

2

C doesn't have new, only C++.

Use calloc instead, found in <stdlib.h>

int *t = calloc(n, sizeof(int));

answered Jan 4, 2012 at 11:10

Pubby

53.3k13 gold badges147 silver badges186 bronze badges

Collectives™ on Stack Overflow

declaration inside function syntax

3 Answers 3

Comments

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related