Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>Many answers seem to focus on the ability to fall through as the <em>reason</em> for requiring the <code>break</code> statement.</p> <p>I believe it was simply a mistake, due largely because when C was designed there was not nearly as much experience with how these constructs would be used.</p> <p>Peter Van der Linden makes the case in his book "Expert C Programming":</p> <blockquote> <p>We analyzed the Sun C compiler sources to see how often the default fall through was used. The Sun ANSI C compiler front end has 244 switch statements, each of which has an average of seven cases. Fall through occurs in just 3% of all these cases.</p> <p>In other words, the normal switch behavior is <em>wrong</em> 97% of the time. It's not just in a compiler - on the contrary, where fall through was used in this analysis it was often for situations that occur more frequently in a compiler than in other software, for instance, when compiling operators that can have either one or two operands:</p> <pre><code>switch (operator-&gt;num_of_operands) { case 2: process_operand( operator-&gt;operand_2); /* FALLTHRU */ case 1: process_operand( operator-&gt;operand_1); break; } </code></pre> <p>Case fall through is so widely recognized as a defect that there's even a special comment convention, shown above, that tells lint "this is really one of those 3% of cases where fall through was desired."</p> </blockquote> <p>I think it was a good idea for C# to require an explicit jump statement at the end of each case block (while still allowing multiple case labels to be stacked - as long as there's only a single block of statements). In C# you can still have one case fall through to another - you just have to make the fall thru explicit by jumping to the next case using a <code>goto</code>.</p> <p>It's too bad Java didn't take the opportunity to break from the C semantics.</p>
    singulars
    1. This table or related slice is empty.
    1. POWhy was the switch statement designed to need a break?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. This table or related slice is empty.
    1. USMichael Burr
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POWhy was the switch statement designed to need a break?
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COIndeed, I think they went for simplicity of implementation. Some other languages supported more sophisticated cases (ranges, multiple values, strings...) at the cost, perhaps, of efficiency.
      singulars
      1. PO
      1. USPhiLho
    2. COJava probably didn't want to break habits and spread confusion. For a different behavior, they would have to use different semantics. Java designers lost a number of opportunities to break from C, anyway.
      singulars
      1. PO
      1. USPhiLho
    3. CO@PhiLho - I think you're probably closest to the truth with "simplicity of implementation".
      singulars
      1. PO
      1. USMichael Burr
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload