Go language conditional statement

Conditional statements

if sentence

if  Boolean expression {
    
	
}

if   Boolean expression {
    

} else {
    

}

if  Boolean expression 1{
    

} else if  Boolean expression 2{
    

} else {
    

}

Other writing ：

//  You can include an optional statement component , There is also a variant （ This variant can only be used in if Play a role in the domain ）
if statement; condition{
    

}
if condition{
    

}

 for example :
	if num := 4;num>0 {
    
		fmt.Printf("num Positive number ")
	}

switch sentence

switch Basic usage of statement

switch Statements are used to perform different actions based on different conditions , every last case Branches are all unique , Test from top to bottom , Until it matches .

switch Statement execution process from top to bottom , Until a match is found , There is no need to add... After the match break.

And if the switch There is no expression , It will match true.

Go Inside switch The default is equivalent to each case Last with break, After the match is successful, it will not automatically execute other case, But out of the whole switch, But you can use fallthrough Enforce the following case Code .

switch var1{
    
	case val1:
			...
	case val2:
			...
	default:
			...
}

You can also test multiple values that may meet the criteria at the same time , Separate them with commas .

matters needing attention ：

​ 1.switch Can act on other types ,case The following values must be the same as switch The type of the variable acting is the same .

​ 2.case Is chaotic .

​ 3.case The last value is unique .

​ 43default Is an optional statement .