Right now, to set all items in an array to, say, 0, I have to loop through the entire thing to preset them.
Is there a function or shortcut which can defaultly set all values to a specific number, when the array is stated? Like so:
int array[100] = {0*100}; // sets to {0, 0, 0... 0}
If you want to set all the values to 0 then you can use:
int array[100] = {0}; //initialize array with all values set to 0
If you want to set some value other than 0 then you can use std::fill from algorithm as shown below:
int array[100]; //not intialized here
std::fill(std::begin(array), std::end(array), 45);//all values set to 45
int array[100] = {0};
should do the job Please refer to cppreference
int a[3] = {0}; // valid C and C++ way to zero-out a block-scope array
int a[3] = {}; // invalid C but valid C++ way to zero-out a block-scope array
If you want to initialize the array using a function's return value:
#include <algorithm>
int generateSomeValue( )
{
int result { };
// some operations here to calculate result
return result;
}
int main( )
{
int array[ 100 ];
std::generate( std::begin( array ), std::end( array ), generateSomeValue );
}
You should use vectors, which are more flexible than array.
#include <iostream>
#include <vector>
int main()
{
std::vector<int>v(100,10); // set 100 elements to 10
}
Try running this: https://onlinegdb.com/2qy1sHcQU
std::vector<int> v (100 /* length */, 42 /* initial value */);{0*100}looks a bit strange. On one hand, 0 * 100 == 0 and correct (answer of Denise). On the other hand, it looks like a repetition of 0 is intended to express. That doesn't work that way. And, btw. 0 is the only possible value for an array initializer in that manner.[0]*3 -> [0, 0, 0]not[0*100] -> [0]. Unrelated: Be careful while using multiplication on lists in python you'd be victim of changes in sublist are relected across the list