Java Fundamentals (Chapter four)

Java Fundamentals (Chapter four)

The syntax of a switch structure (switching statement)

switch (expression) {-------[dream1] type is int, char

CASE constant 1:---------[dream2]case structure can have multiple

Statement Block 1

break;---------[DREAM3] program jumps out of the switch structure

Case constant N: The value of the---------[DREAM4] constant cannot be the same

Statement block N

Break

Default: Same as else in----------[DREAM5] and if structures

Statement block

Break

}

Second, switch structure use occasions: int \char 2 types of equivalence judgment to use

Iii. the similarities and differences between switch structure and if structure

Same point: equal judgment can be achieved

Different points:

L syntax is different

L use different occasions.

n if structure, focusing on range judgment

N-switch structure, focusing on equivalence judgments, types can only be int, char type

L Efficiency

N in the equivalence judgment, the switch structure efficiency is higher than the IF structure

Iv. exception handling--hasnextint ();

Determines whether an integer

if (Input.hasnextint ()) {//Boolean type

code block

}

Java Fundamentals (Chapter four)