C # if, ifelse statement,

C # if, ifelse statement,

1. The if statement is determined based on the value of the Boolean expression.

The if statement can be either of the following methods:

Code(1)if(boolean)       do (2)if(boolean){ do}

Generally, the second method is used, because the first method only executes the first statement after the if condition.

For example:

Codeif(Boolean)  Console.WriteLine("ok1");  Console.WriteLine("ok2"); 

No matter whether the value of boolean is true or false, ok2 will always output, but it will be different if you use the second method.

2. if-else statement

The if -- else statement and the if statement have the same judgment conditions. The code is executed based on the boolean result of the condition. However, if-else has an alternative opportunity than if. Just like sending a prize in a competition, if you lose all the prizes, you can also get a consolation prize if you add an else.

If-else statement format is, must have braces

Codeif(Boolean){  do-something;}else{  do-something;}

If we only want to perform simple if-else operations, we can use a very simple method provided by C # without using the if-else statement, such

Codeint i=0;

      int j=0;

If (I> 0) {j = 1;} else {j = 2 ;}

It is easy to assign an I value. We can abbreviated it to int I = 0; int j = I> 0? .

3. Statement nesting

If, if-else statements can be nested with each other

Codeif(boolean){   if(boolean){         do something;     }else{       do something;    }}if(boolean){     if(boolean){    do something;   }}else{   if(Boolean){   do something; }}

Today, it is time to take a moment to carefully understand the knowledge.