This question already has answers here:
How do I determine the size of my array in C?
(24 answers)
Closed 4 years ago.
We have been given a large array of unknown size with elements given , is there any function or something other through which we can find the size of that array in language C
int a[]={4,6,4,26,3,2,5,7,3,7,3,2,5,4,6,3,7,232,6,32,6,3,7,3,6,2,5,7,3,6,3,6,36,3,67,23,6};
The size in bytes you can get by
sizeof(a);
The number of elements in that array you can get by
sizeof(a)/sizeof(a[0]);
Related
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How dangerous is it to access an array out of bounds?
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No out of bounds error
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How many members calloc allocates in C [duplicate]
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Closed 1 year ago.
Here I have declared an integer array of size 2 but I am able assign more than 2 elements to the array and also print them but the array size is indicated as of size 8bytes before and also after assigning a value to it.
int main()
{
int a[2];
printf("size is %d\n",sizeof(a));
a[0]=1;
a[1]=2;
a[2]=3;
a[3]=4;
a[4]=5;
printf("%d %d %d %d\n",a[0],a[1],a[2],a[3],a[4]);
printf("size is %d\n",sizeof(a));
}
Output
size is 8
1 2 3 4
size is 8
So is it possible to assign more elements than the specified size to an array? If yes is it only applicable if you declare the array in this fashion and can this be applied to any type of array in c?
This question already has answers here:
How do I determine the size of my array in C?
(24 answers)
Closed 3 years ago.
I know this is a very basic question in C, so I apologize beforehand if this is naive: I'm just learning the basics a few days in.
int main() {
// initialize the variables
int num_whitespaces, num_other;
int num_digits[10];
printf("%lu", sizeof(num_digits));
}
This prints 40, which seems odd to me. Why wouldn't this print 10, which would be the length of the array in javascript or so.
sizeof returns the size in memory. Not the length of something.
Same for C++ and this link has the same example :) https://en.cppreference.com/w/cpp/language/sizeof
size of empty class: 1
size of pointer: 8
size of array of 10 int: 40
size of array of 10 int (2): 40
length of array of 10 int: 10
length of array of 10 int (2): 10
size of the Derived: 8
size of the Derived through Base: 4
Getting the length is pretty difficult in C: array_length in C
sizeof returns the size of an object in bytes
An int is 4 bytes. sizeof(int[10]) is 40.
This question already has answers here:
Why int array[1000][1000] is memory issue in C program? [duplicate]
(1 answer)
Getting a stack overflow exception when declaring a large array
(8 answers)
Closed 5 years ago.
I'm using a pretty simple 2D array to store values (it's part of a mandelbrot set program).
int toBeWritten[xres][yres]; // xres and yres are calculated based on command line arguments
The 2D array works fine until my numbers get larger.
These, for example, work:
int toBeWritten[1024][1160];
int toBeWritten[2048][2321];
But when the size of the array grows to this:
int toBeWritten[4092][4637]; // the size I start getting seg faults
int toBeWritten[8192][9284]; // the largest size I want to get to
I get a seg fault if I try and access this array at any point after creating it.
Is it simply too big? Am I not allocating memory correctly?
If I can't make a 2D array this large, how could I store the values instead?
Thanks for any help!
This question already has answers here:
Swift 3 2d array of Int
(2 answers)
Closed 5 years ago.
var tri = [[Int]]();
tri[0][0] = 321;
This code causes this error:
fatal error: Index out of range
What's wrong?
You're accessing the first element of the first subarray of the array. But your array doesn't contain any subarrays, so it crashes.
This question already has answers here:
Fortran increase dynamic array size in function
(3 answers)
Fortran array automatically growing when adding a value
(1 answer)
How to increase array size on-the-fly in Fortran?
(3 answers)
Closed 5 years ago.
I am trying to allocate an array and want to resize the array ie., grow the array size as and when required in the program.
My sample code looks like this
program main
implicit none
integer, allocatable, dimension(:)::test1
integer i, c1, c2
c1=10
c2=5
allocate(test1(1:c1))
! I basically want to do this
!allocate(test1(c1+1:c2))
end program main
How do I do this?