cppNEWBIE "bool Save(const char *name) const;" why const???

Hi,
I am new to cpp
I have some programs and have a question about "identifiers at the end of the method name"
When and why are they necessary?
For example, Consider the following code

Code:

class Table1D
{
...
	bool Save(const char *name) const;	
...
}

In other languages I will simply write something like

Code:

 bool Save(const char *name)

(without the const identifier)
Another example is here:

Code:

float Triangle(const blob &p1, const blob &p2) const { return 0.5f*fabs((p1.x-x)*(p2.y-y)-(p1.y-y)*(p2.x-x)); }

Why "const" goes to the end, and where should I put an identifier in the end?

Thanks.

This means that this is const in the method, i.e the method will not modify the class members. Therefore you can call the Save method even if you don't have the right to modify the Table1D instance:

Code:

void foo(const Table1D& table)
{
    ...
    table.Save(); //OK, won't modify table
}

If we consider that Save lacked a const modifier at the end, the following would not compile:

Code:

void foo(const Table1D& table)
{
    ...
    table.Save(); // Not OK, since we cannot promise Save won't modify table.
    ...
}

thanks anon and Elysia.