C++ Vector assign()

This function assigns new values to the vector and replacing the old ones.

Syntax

Consider a vector v to whom the value is to be assigned. Syntax would be :

v.assign(first,last);
v.assign(n,val);

Parameter

(first,last) :It defines the range.first is an input iterator pointing to the first element and last is an input iterator refering to the past the last element.

n : Number of times the value to be occurred.

val : It defines the value which is to be assigned.

Return value

It does not return any value.

Example 1

Let's see a simple example.

#include<iostream>
#include<vector>
using namespace std;
int main()
{
	vector<int> v{1,2,3,4,5};
	vector<int> v1;
	v1.assign(v.begin()+1,v.end()-1);
	for(int i=0;i<v1.size();i++)
	std::cout<<v1[i] <<std::endl;
	return 0;
}

Output:

2
3
4

In this example, vector v containing integer values is assigned to the vector v1 using assign() function.

Example 2

Let's see a another simple example.

#include<iostream>
#include<vector>
using namespace std;
int main()
{
vector<char> v;
v.assign(5,'C');
for(int i=0;i<v.size();i++)
std::cout<< v[i] << " ";
return 0;
}

Output:

C CCCC

In this example, v is assigned value 'C' five times using assign() function.

Example 3

Let's see a simple example.

#include<iostream>
#include<vector>
using namespace std;
int main()
{
vector<char> v{'C','+','+'};
vector<char> v1;
v1.assign(v.begin(),v.end());
for(int i=0;i<v.size();i++)
std::cout<< v[i];
return 0;
}

Output: