Solve PHP error: non-terminable link problem

Solution to PHP error: non-terminable link problem

In PHP development, we often encounter some error messages, one of the common error messages is " Fatal error: Cannot break/continue 1 level in... This error is usually caused by the incorrect use of break or continue in the loop structure. This article will analyze this error and provide a solution.

The reason for this error is the use of break or continue in the loop structure, but these two statements can only be used in for, foreach, while and do-while loops. If used elsewhere, an error will be reported.

The following is a simple code example to explain the cause of this error:

<?php
for ($i = 1; $i <= 3; $i++) {
    echo "外层循环： $i <br>";
    for ($j = 1; $j <= 3; $j++) {
        echo "内层循环： $j <br>";
        continue 2;
    }
}
?>

In the above example code, we use two levels of nested for loops, and The continue statement is used in the inner loop. The function of the continue statement is to end this iteration of the current loop and continue with the next iteration. However, the number 2 followed by the continue statement used in the above code indicates the level of the loop to be terminated, but the level of the outer loop is 1, so an "unterminable link" error is raised.

In order to solve this problem, we need to correct the code according to the actual situation. In this example, we can eliminate the error by modifying the level of the continue statement. The following is a modified code example:

<?php
for ($i = 1; $i <= 3; $i++) {
    echo "外层循环： $i <br>";
    for ($j = 1; $j <= 3; $j++) {
        echo "内层循环： $j <br>";
        continue 1;
    }
}
?>

In the modified code above, we change the number after continue to 1, which is consistent with the level of the outer loop, so that we can continue to the next time smoothly. Iterate without error.

In addition, to avoid this kind of error, you also need to pay attention to when using the break or continue statement to ensure that the loop structure used is correct, and the number after continue must match the level of the loop structure.

To summarize, PHP error "unterminable link" is often caused by incorrect use of break or continue statements in loop structures. To solve this problem, you need to pay attention to the position of using these two statements and the level of the loop structure, and ensure that they match. Through the above examples and solutions, we hope to help everyone better understand and solve this problem.

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