Why we use switch in c language in case of if....else statement?

Have you never heard of nested if...then...else?

But hey thanks for sharing.

The switch statement is a short-hand form of an if-else chain, provided the test is performed on an expression returning an 'integral type' ( see The C++ switch statement[^] at MSDN).
That is the if-else chain is more general and powerful, while the switch statement is often handy.
:)

Not sure exactly what you're asking here, but... If it's what's the point of a switch statement then about the only difference between a switch and a if/else is syntax. All modern compilers (and I'm including VC++2005 onwards, gcc 3.x onwards and EDG) will generate the same sort of code for a switch as it will for a nested if/else on an integer.

So in both cases the compiler will generate a jump table if the ints switched/ifed on are sequential and otherwise will use tests and jumps. If you use several ranges of sequential ints it will use tests and jumps to get you to the right jump table.

[As a complete aside, if you've got lots of sequential IDs and you're writing well factored code with loads of functions you'll usually end up doing better by avoiding both and implementing a function table. This has the added advantage of making the switching/iffing code indepenent of the values switched on.]

Cheers,

Ash

// When we use switch in c language in case of if....else statement?

It is comfortable,
when you would check the multiple value variants
of a single variable (given or returned) only... :)