do{
    // Business logic
}while(false);
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I found a strange code in the company reading the project code, which aroused my curiosity. After searching the information, I found that this has the following wonderful use, hereby record.

  1. Implement goto-like functions to simplify code nesting

    In code, it’s not unusual for a second judgment to depend on the result of the first judgment, or even a third judgment to depend on the result of the second judgment. The conditional judgment can only be written in the following form. This is also a lot of logical code if… Else is one of the reasons for nesting many layers.

    if(condition1){
    // code segment 1
    if(condition2){
        // Code segment 2
        if(condition3){
            // code segment 3}}}Copy the code

    But nested judgments make it hard to untangle code logic and error-prone. If you use do… While solves this multiple nesting problem

    do{
    if(! condition1)break;
    // code segment 1
    if(! condition2)break;
    // Code segment 2
    if(! condition3)break;
    // code segment 3
}while(false)
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