You may not know the switch

One:

Int I = 0;

Switch (I)
{
Case 0:
Console. writeline ("0 ");
Case 1:
Console. writeline ("1 ");
Break;
}

// Here, you want to execute

// Console. writeline ("0"), and then "fall through" to the lower layer to execute case 1.

// However, "fall through" is not allowed in C. Unless none of the "case 0" statements exist.

However, you can use the GOTO statement to implement "fall through"

int i = 0;switch (i){    case 0:        Console.WriteLine("0");        goto case 1;    case 1:        Console.WriteLine("1");        break;}

In C #, every case XXX is a tag, so you can use the GOTO statement to redirect.

Two:

Here, the default statement does not do anything, but does not add break;

The prompt is as follows:

C # Strictly control that the branches of each switch are not allowed to run through ("fall through"). For example, sometimes you may look like the following:

This statement is completely legal.

Three:

Sometimes you define variables in case, but the variables may have the same name, for example:

Two identical variables, Y, are defined in case 0 and Case 1. The Compiler prompts the following error:

To solve this problem, add "{}" to convert the case statement into a BLOCK statement.

Of course, there is also an unknown solution, as shown below:

Four:

Suppose you have a method m and the code is as follows:

int M(bool b){    switch (b)    {        case true: return 1;        case false: return 0;    }}

It is obvious that B has only two values, one being true and the other being false, but the compiler fails. The prompt is:

The compiler considers that every switch structure can be executed and does not execute it. However, method M must have an int return value, so the compiler prompts an error.

The solution to this problem is also simple:

int M(bool b){    switch (b)    {        case true: return 1;        default: return 0;    }}

Or:

int M(bool b){    return b ? 1 : 0;}

Original article: four switch oddities

One:

Int I = 0;

Switch (I)
{
Case 0:
Console. writeline ("0 ");
Case 1:
Console. writeline ("1 ");
Break;
}

// Here, you want to execute

// Console. writeline ("0"), and then "fall through" to the lower layer to execute case 1.

// However, "fall through" is not allowed in C. Unless none of the "case 0" statements exist.

However, you can use the GOTO statement to implement "fall through"

int i = 0;switch (i){    case 0:        Console.WriteLine("0");        goto case 1;    case 1:        Console.WriteLine("1");        break;}

In C #, every case XXX is a tag, so you can use the GOTO statement to redirect.

Two:

Here, the default statement does not do anything, but does not add break;

The prompt is as follows:

C # Strictly control that the branches of each switch are not allowed to run through ("fall through"). For example, sometimes you may look like the following:

This statement is completely legal.

Three:

Sometimes you define variables in case, but the variables may have the same name, for example:

Two identical variables, Y, are defined in case 0 and Case 1. The Compiler prompts the following error:

To solve this problem, add "{}" to convert the case statement into a BLOCK statement.

Of course, there is also an unknown solution, as shown below:

Four:

Suppose you have a method m and the code is as follows:

int M(bool b){    switch (b)    {        case true: return 1;        case false: return 0;    }}

It is obvious that B has only two values, one being true and the other being false, but the compiler fails. The prompt is:

The compiler considers that every switch structure can be executed and does not execute it. However, method M must have an int return value, so the compiler prompts an error.

The solution to this problem is also simple:

int M(bool b){    switch (b)    {        case true: return 1;        default: return 0;    }}

Or:

int M(bool b){    return b ? 1 : 0;}

Original article: four switch oddities