Java series (5)-process control statements and java statements

Java series (5)-process control statements and java statements

1. Ordered Structure

1. if statement

(1) legend

(2) three formats

   
A: Format 1
    
    
B: Format 2
    
    
C: Format 3
    
 

2. swich statement

Legend:

Format:

[Note] the input value can be byte, short, int, char, enumerative after JDK5, and string after JDK7;

3. Loop statements

Legend:

(1) for Loop

(2) while Loop

Legend:

Usage:

(3) do... While Loop

Legend:

Usage:

(4) differences between for and while

   
A: usage differences
    
[The control condition variable of the for statement cannot be used after the loop ends, but the while statement can be used again]
    
B: differences in understanding
    
[For is suitable for the determination of a range, while is suitable for loops with unclear numbers]
 

(5) differences between the three cycles

   
A: do... The while LOOP must be executed at least once.
    
B: for and while must first determine whether the condition is true before deciding whether to execute a loop
 

4. Control jump statements

(1) break: Meaning of Interruption

   
A: It is used in loop and switch statements, and the exit application scenario is meaningless.
    
B: role:
    
[A. Jumping out of a single loop]
    
    
[B. jump out of a multi-layer loop and use the tag statement together]
    
    
 

(2) continue: continue

Purpose: jump out of a loop and enter the next execution.

(3) return: return

   
A: Used to end method execution.
    
B: The program will not be executed in the future if return is encountered.