Similarities and differences between vector and array (notes)

identical ：

         An array with the vector The similarity is that they can store objects of the same type , And these objects themselves have no names , Need to access... From its location .

Different ：

         An array with the vector The biggest difference is , The size of the array is fixed , You can't add additional elements to the array at will , Although runtime performance is better in some situations , But with the vector Compared with the loss of flexibility .

         say concretely , The dimension of the array has been determined at the time of definition , If we want to change the length of the array , You can only create a larger new array , Then copy all the elements of the original array to the new array . We can't be like vector Use like that size Function to directly obtain the dimension of the array . If it's a character array , You can call strlen Function to get the length of the string ; If it's another array , Only use sizeof(array) /sizeof(array [0]) Calculate the dimension of the array .