Say I have the following declared variable:
char mychararray[35];
and I want to set every character in the array to a blank space... How can I do that?
My instructor told me all I had to do was put
mychararray = "";
but that didn't work at all...
Am I using an outdated version of Visual Studio (2012), or is this just a bad initialization? If it is the latter, please explain how to make all the characters a blank space.
Thanks in advance!
You can initialize it the way your instructor suggested as you declare the array:
char mychararray[35] = "";
It will set the array to an empty string.
If you want to make it an empty string later, then you can just do
mychararray[0] = '\0';
If you want to make it an array consisting of 34 spaces (35th character being null terminator), then
memset(mychararray, ' ', 34);
mychararray[34] = '\0';
char mychararray[35] = ""; I updated my answer.
If there are fewer initializers than there are array elements, each element not explicitly initialized shall be zero-initialized.That is not initialization, it's assignment. For initializing an array when declaring it, you can write:
char mychararray[35] = "";
If you already have an array and want to set it to zero, you can use std::fill:
#include <algorithm>
#include <iterator>
int main()
{
char c[35] = "Hello, world!";
std::fill(std::begin(c), std::end(c), '\0');
// c will contain only zeros now.
}
However, C-style arrays are not very popular in modern C++. Prefer using std::string (which you can clear using the clear() member function), or std::array<char, N> if you need the size to be known at compile-time.
std::memset is your friend.
memset(mychararray, ' ', 34);
mychararray[34]='\0';
If you want to initialize the array with all elements being '\0', you have a neater way through aggregate initialization:
char mychararray[35] = {};
std::fill is safer, the memset function should only be used with bytes.
char array specific answer. Since the byte being specified is a char literal, overflow isn't a worry.Although you could use std::fill_n(array, 35, ' '), you're probably better of using an std::string, the preferred string class in C++. Don't have to care about zero-termination or anything.
std::string blanks(35, ' ');
C++ doesn't initialie char to ' ' (which has the ascii value 0x20, btw); in fact, array initialization without specifying what to use for initialization doesn't necessarily take place (arrays in local scope are left uninitialized).
char myarray[35] = "";does work. All characters will be'\0'.= ""wasn't just some bad initialization.