c++ - Assigning parameter value in function declaration? -


i don't understand why in constructor declaration, input parameter assigned 2.

what mean? mean default (unless else passed), size 2?

graph(int size = 2);

i've never seen syntax this, don't know how google :/

thanks in advance!

you're right, parameter value 2 default.

so can call normally:

graph g(5);

in case size equal 5,

or can call without providing value:

graph g;

in case size equal 2.

note: graph g(); function declaration, not construction/initialization. c , c++ allow declare functions inside other functions. graph g(); declaration of function g takes no arguments , returns graph object value.


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