vector vec1; // Initialization of an empty vector of integers
vector vec2(5); // Initialization of a vector of integers with 5 default-initialized elements
vector vec3(5, 10); // Initialization of a vector of integers with 5 elements each initialized to 10
vector vec4{1, 2, 3, 4, 5}; // Initialization of a vector of integers with specified elements 1, 2, 3, 4, and 5