corejavae10v1p3.8 3rd Java BASIC Programming Structure-3.8 control flow

Process control can be achieved by using conditional statements, loop statements, and so on.

3.8.1 Block scope (block scope)

A block is a section surrounded by a pair of curly braces. He specifies the scope of a variable's existence, with a method's operating range. Repeating the definition of a variable in a nested block is not allowed in Java.

3.8.2 Conditional statements

if (condition) statement

12 ...}

 if  (yoursales >= target) {performance  = "satisfactory" ;bonus  = + 0.01 * (yoursales- target);}  else  {performance  = "unsatisfactory" ;bonus  = 0< Span style= "COLOR: #000000" >;}  

if (Yoursales >= 2 *= "excellent"=;} Else if (Yoursales >= 1.5 *= "Fine"=;} Else if (yoursales >== "satisfactory"=;} Else {System.out.println ("You ' re fired");}

3.8.3 Loop Statements

1.while Cycle

while (condition) statement

 while (Balance < goal) {    + = payment    ; double interest = balance * interestrate/100;     + = interest;    Years+ + + "years.");

2.do-while Cycle

Do statement while (condition); Be aware of;

 Do {    + = payment    ; double interest = balance * interestrate/100;     + = interest;    year ++    ; // Print Current balance     . . .     // ask if ready to retire and get input     . . .}  while (Input.equals ("N"));

3.8.4 fixed number of cycles (determinate loop)

1.for Cycle

 for (int i = ten; i > 0; i--)    System.out.println ("Counting down ... "+ i);

3.8.5 Multi-Select Switch statement

Scanner in =NewScanner (system.in); System.out.print ("Select an option (1, 2, 3, 4)");intChoice =in.nextint ();Switch(choice) { Case1:. . . Break; Case2:. . . Break; Case3:. . . Break; Case4:. . . Break;default://Bad input. . . Break;}

The case label (that is, the variable type followed by switch) can be:

? Char, BYTE, short, int and its wrapper class constant expression
? Enum type
? String literals are supported starting from Java SE 7.

String input = ...; Switch (Input.tolowercase ()) {case//  OK since Java SE 7...  Break ;. . .}

3.8.6 jump out of the loop

1. Although Java retains the Goto keyword, it is not recommended to use a goto statement. Generally use break to jump out of a loop. Java supports tagged break statements to jump out of multiple loops. It is equivalent to giving each loop a name and jumping out of which loop you can specify.

label:{ ... if  Break // exits block . . .} // Jumps here is the break statement executes

Examples are as follows:

 while (Years <=+ + + payment; double interest = balance * interestrate/100+ = interest; if  Break ; years+ +;}

Scanner in =NewScanner (system.in);intN;read_data: while(. . .)//This loop statement are tagged with the label{. . . for(. . .)//This inner loop was not labeled{System.out.print ("Enter A number >= 0:"); n=in.nextint ();if(N < 0)//should never Happen-can ' t go on BreakRead_data;//Break out of Read_data loop. . .}}

2.continue statements

Jump out of this cycle

corejavae10v1p3.8 3rd Java BASIC Programming Structure-3.8 control flow