How to access object value from array angular 7?

Question

How to access object value from array angular 7?

I have array have one object as below

res = [{"totalCount:"557"}]

as above res have array of object 

i need to get value of 557

so how to get it 

and what variable will recieve value 557 int or any 

can you help me how to get value 557 from array of object above 

and what variable type it will store that