What is the “continue” keyword and how does it work in Java?

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温柔的废话
温柔的废话 2020-11-22 11:34

I saw this keyword for the first time and I was wondering if someone could explain to me what it does.

  • What is the continue keyword?
  • How
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  • 2020-11-22 11:34

    I'm a bit late to the party, but...

    It's worth mentioning that continue is useful for empty loops where all of the work is done in the conditional expression controlling the loop. For example:

    while ((buffer[i++] = readChar()) >= 0)
        continue;
    

    In this case, all of the work of reading a character and appending it to buffer is done in the expression controlling the while loop. The continue statement serves as a visual indicator that the loop does not need a body.

    It's a little more obvious than the equivalent:

    while (...)
    { }
    

    and definitely better (and safer) coding style than using an empty statement like:

    while (...)
        ;
    
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  • 2020-11-22 11:44

    Basically in java, continue is a statement. So continue statement is normally used with the loops to skip the current iteration.

    For how and when it is used in java, refer link below. It has got explanation with example.

    https://www.flowerbrackets.com/continue-java-example/

    Hope it helps !!

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  • 2020-11-22 11:45

    Generally, I see continue (and break) as a warning that the code might use some refactoring, especially if the while or for loop declaration isn't immediately in sight. The same is true for return in the middle of a method, but for a slightly different reason.

    As others have already said, continue moves along to the next iteration of the loop, while break moves out of the enclosing loop.

    These can be maintenance timebombs because there is no immediate link between the continue/break and the loop it is continuing/breaking other than context; add an inner loop or move the "guts" of the loop into a separate method and you have a hidden effect of the continue/break failing.

    IMHO, it's best to use them as a measure of last resort, and then to make sure their use is grouped together tightly at the start or end of the loop so that the next developer can see the "bounds" of the loop in one screen.

    continue, break, and return (other than the One True Return at the end of your method) all fall into the general category of "hidden GOTOs". They place loop and function control in unexpected places, which then eventually causes bugs.

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  • 2020-11-22 11:46

    Let's see an example:

    int sum = 0;
    for(int i = 1; i <= 100 ; i++){
        if(i % 2 == 0)
             continue;
        sum += i;
    }
    

    This would get the sum of only odd numbers from 1 to 100.

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  • 2020-11-22 11:46

    Consider an If Else condition. A continue statement executes what is there in a condition and gets out of the condition i.e. jumps to next iteration or condition. But a Break leaves the loop. Consider the following Program. '

    public class ContinueBreak {
        public static void main(String[] args) {
            String[] table={"aa","bb","cc","dd"};
            for(String ss:table){
                if("bb".equals(ss)){
                    continue;
                }
                System.out.println(ss);
                if("cc".equals(ss)){
                    break;
                }
            }
            System.out.println("Out of the loop.");
        }
    
    }
    

    It will print: aa cc Out of the loop.

    If you use break in place of continue(After if.), it will just print aa and out of the loop.

    If the condition "bb" equals ss is satisfied: For Continue: It goes to next iteration i.e. "cc".equals(ss). For Break: It comes out of the loop and prints "Out of the loop. "

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  • 2020-11-22 11:49

    "continue" in Java means go to end of the current loop, means: if the compiler sees continue in a loop it will go to the next iteration

    Example: This is a code to print the odd numbers from 1 to 10

    the compiler will ignore the print code whenever it sees continue moving into the next iteration

    for (int i = 0; i < 10; i++) { 
        if (i%2 == 0) continue;    
        System.out.println(i+"");
    }
    

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