Scala series: control structures and functions

In Java, expressions represent values, and statements represent execution actions. For example, expression 1 + 1 indicates the value, and thread. Start () indicates the execution action.

All Syntax structures have values, even if unit is not used.

 

If/else statement

Has a value, which is the value of the expression following if or else.

Example: Val S = If (x> 0) 1 else 0;

Equivalent to VaR S: Int = 0; If (x> 0) S = 1 else S = 0;

Val S2 = If (x> 0) "string" else 1;

S2 is of any type

Val S3 = If (x> 0) 1;

The S3 type is also any, but when x <= 0, the S3 value is unit, and the unit class indicates "no useful value", which is written ()

No switch statement

 

 

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Scala series: control structures and functions