Jump statement and debugger

 

break（ Change program control flow ）

Action scenario ：switch Select structure and cycle structure

effect ：

        stay switch Encountered in the selection structure break, End the whole switch structure , perform switch Select the code behind the structure ;

        Encountered in the loop structure break, Then all subsequent operations of the whole cycle structure are ended , Execute the code after the loop structure

Be careful ：

        break General combination if Select statements to use together

        //  Cyclic output 1-20, When output to 10, All the following numbers are no longer output 
		
		for (int i = 1; i <=20; i++) {
			System.out.println(i);
			// Judge i Value , See if it has arrived 10, If it comes to 10 了 , It should end the whole for loop 
			if(i==10){
				break;// End the whole thing for loop 
			}
			
		}

continue

Action scenario ： It can only act in the circular structure

effect ：

        End the present （ This time ） Cycle subsequent operations , Continue with the next cycle

Be careful ：

        continue General combination if Select statements to use together

// Cyclic output 1-20, No output 10
for (int i = 1; i <=20; i++) {
			if(i==10){
				continue;				
			}
			System.out.println(i);
		}

contrast break and continue

         Use occasion

                break Commonly used in switch In structure and cyclic structure

                continue Generally used in circular structures

         effect （ In cyclic structure ）

                break Statement terminates a loop , The program jumps to the next statement outside the loop block

                continue Jump out of this cycle , Enter next cycle

                 The same is true of the double cycle  

return： End the execution of the current method and exit , Return to the statement that called the method  

Why do you need program debugging

         Errors sometimes occur in the process of writing programs , But it's hard to find and locate errors , Is there a good way ？

                 Find program errors by reading code or adding output statements

                 When the program structure becomes more and more complex , Special techniques are needed to find and locate errors , Namely “ Program debugging ”

What is program debugging

         When the program goes wrong , We hope so

         

         When the program is executed, it flashes and ends , How to make the program run step by step ？

         

 

The breakpoint ： Lines of code where the program pauses   

To set breakpoints ： Double click the number in the code line

To test a program , You need to set breakpoints at the beginning and end

After setting the breakpoint , Click on this little beetle chart (debug), You can operate the test program