valarray apply() in C++
The apply() function is defined in valarray header file. This function returns a valarray with each of its elements initialized to the result of applying func to its corresponding element in *this.
Syntax:
valarray apply (T func(T)) const; valarray apply (T func(const T&)) const;
Parameter: This method accepts a mandatory parameter func which represents the pointer to the function taking an argument of type T.
Return Value: This method returns a valarray object with the results of applying func to all the elements of *this.
Below programs illustrate the above function:
Example 1:-
// C++ program to demonstrate // example of apply() function. #include <bits/stdc++.h> using namespace std; int main() { // Initializing valarray valarray<int> varr = { 15, 10, 30, 33, 40 }; // Declaring new valarray valarray<int> varr1; // Using apply() to increment all elements by 5 varr1 = varr.apply([](int x) { return x = x + 5; }); // Displaying new elements value cout << "The new valarray " << "with manipulated values is : "; for (int& x : varr1) cout << x << " "; cout << endl; return 0; } |
Output:
The new valarray with manipulated values is : 20 15 35 38 45
Example 2:-
// C++ program to demonstrate // example of apply() function. #include <bits/stdc++.h> using namespace std; int main() { // Initializing valarray valarray<int> varr = { 15, 10, 30, 33, 40 }; // Declaring new valarray valarray<int> varr1; // Using apply() to decrement all elements by 5 varr1 = varr.apply([](int x) { return x = x - 5; }); // Displaying new elements value cout << "The new valarray" << " with manipulated values is : "; for (int& x : varr1) cout << x << " "; cout << endl; return 0; } |
Output:
The new valarray with manipulated values is : 10 5 25 28 35
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