The for loop length property for arrays doesn't seem to work for me code
#include <iostream>
int main()
{
char a[] = {"H", "e", "l", "l", "o"};
for (int i = 0; i < a.length; i++)
{
std::cout << a[i];
//I also tried printf with stdlib.h
}
}
But it gives an error. Did I do it right?
You are using an array. It is a primitive type. So there are not member functions on it like objects. You have to use a vector instead. You also have to initialize the vector (or array) with chars not strings.
int main()
{
std::vector<char> a = {'H', 'e', 'l', 'l', 'o'};
for (int i = 0; i < a.size (); i++)
{
std::cout << a[i];
}
}
If you really want to use an array you have to define the size function as follow:
template<class T, size_t N>
constexpr size_t size (T (&)[N]) { return N; }
int main()
{
char a[] = {'H', 'e', 'l', 'l', 'o'};
for (int i = 0; i < size (a); i++)
{
std::cout << a[i];
//I also tried printf with stdlib.h
}
}
To get the length of an array in c++ you can use:
int length = sizeof(a) / sizeof(a[0]);
Array is not an object in c++ thus it cannot have fields.
Plain arrays define no functions but you can use the library begin and end functions introduced with c++11:
#include <iostream>
int main()
{
char a[] = { 'H', 'e', 'l', 'l', 'o' }; // use chars instead of strings
for (auto it = std::begin(a); it != std::end(a); ++it) // use iterators
{
std::cout << *it;
}
}
Or even shorter using a range for as pointed out by BarryTheHatchet:
#include <iostream>
int main()
{
char a[] = { 'H', 'e', 'l', 'l', 'o' };
for (auto c : a)
{
std::cout << c;
}
}
Keep in mind that the list initialization as above doesn't include a NULL char. If you declare your array with a NULL char at the end you can use cout directly without for loop:
char a[] = { 'H', 'e', 'l', 'l', 'o', '\0' }; // explicit NULL with list initialization
std::cout << a;
char b[] = "Hello"; // implicit NULL when using a literal
std::cout << b;
You can't do that. You can get the size of an array a using:
sizeof(a)/sizeof(a[0]);
But since you are in C++ you should use an std::vector like this:
std::vector<char> a;
And then get the size:
a.size();
Here a is a character array.. It doesn't have any member called "length"..This member is found in Java not C++. For this problem you can use "sizeof()" function function.
