C language pointer and address

1. How to exchange values of two numbers

Void swap (int * a, int * B)

{

Int TEP = * A; // * A is actually the value of primary function a, and a is the address of primary function a's value.

* A = * B;

* B = TEP;

}

2. How to sort two-dimensional array Functions

Void DESC (INT (* A) [10], int I ){

// In this way, you can directly use the [I] [J] operation in this function, just like in the main function.

// Int (* A) [10] indicates a two-dimensional array with 10 columns. Then, write DESC (A, 5) in the main function ), this is a two-dimensional array with 5 rows.

For (INT n = 0; n <5; n ++)

For (Int J = 0; j <10; j ++)

{

If (a [n] [J] <a [n] [J + 1]) // you can determine the size. If the size is small, you can change the position of the backend.

Swap (& A [I] [J], & A [I] [J + 1]); // call the previous function to implement value exchange. Here is the address passed in, not a value.

}

 

}

* P: the number of pointers is the same. The number of (n-1) * after the first pointer is the address. Only the first pointer represents the pointer.

* ** P actually points to an address.

 

}