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If my javascript ajaxes away to my server and returns an ID of 49 in the plain text format of [49] is there a way in which i an do something like this... (i have tested and doesnt work)

switch(data)
{
    case '[*]':
        (..etc.)
    break;
}

Where the wildcard is the * and i want to make sure it is enclosed within two square parenthesis?

Because i need to check that there wasnt another word returned like error and i am reserving the default for unexpected errors, any ideas? :) Thanks!

If my javascript ajaxes away to my server and returns an ID of 49 in the plain text format of [49] is there a way in which i an do something like this... (i have tested and doesnt work)

switch(data)
{
    case '[*]':
        (..etc.)
    break;
}

Where the wildcard is the * and i want to make sure it is enclosed within two square parenthesis?

Because i need to check that there wasnt another word returned like error and i am reserving the default for unexpected errors, any ideas? :) Thanks!

• javascript
• jquery
• wildcard
• switch-statement

Share Improve this question Follow asked Feb 16, 2010 at 7:39 tarnfeldtarnfeld 26.6k4444 gold badges112112 silver badges147147 bronze badges 1

• 1 @Tracker1's answer should really be the correct one considering the title of the question. – kb. Commented Feb 16, 2010 at 8:26

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4 Answers 4

Sorted by: Reset to default 19

You can do a switch on true explicitely, which will use evaluation on each case statement.

switch (true) {
    case ((/^\[\d+\]$/).test(data)):
       //matches data;
       break;
    case (data == "something else"):
       //...
       break;
    default:
       //...
}

However, if you have less than say 4-5 cases, it would be better to use if/else if/else if/else blocks.

if ((/^\[\d+\]$/).test(data)) {
       //matches data;
} else if (data == "something else") {
       //...
} else {
       //...
}

I usually do some error trapping in my response methods for service/rest calls so that I almost always return a proper json with an error property if there is an error.

try {
  if (response.responseText.indexOf("<html") >= 0) { 
    throw response.responseText;
  }

  var data = JSON.parse(response.responseText);
  if (data.error) 
    throw data.error;

  //handle response data object.
  if ((/^\[\d+\]$/).test(data)) {
    //matches data;
  } else if (data == "something else") {
    //...
  } else {
    //...
  }
} catch(err) {
  if (err && err.message) {
      //use err.message
  } else if (err && err.toString().indexOf("<html") >= 0) {
      //handle error text
  }
}

You could create a list of patterns and associated callbacks and do a simple loop and check for matches. For example:

    var patterns = [];

    function myCallback(){ document.write('myCallback!'); }
    function myOtherCallback(){ document.write('myOtherCallback!'); }
    function myLastCallback(){ document.write('You will never see me!'); }

    patterns.push({'pattern':new RegExp(/\[.+\]/),'callback': myCallback});
    patterns.push({'pattern':new RegExp(/.+/),'callback':myOtherCallback});
    patterns.push({'pattern':new RegExp(/A-Z{3}/),'callback':myLastCallback});

    var f = "[49]";
    for(var i=0;i<patterns.length;i++){
        if(patterns[i].pattern.test(f)){
            patterns[i].callback();
        }
    }

Which outputs the following:

myCallback!myOtherCallback!

You could try to use if else and regex for matching wildcard patterns.

Assuming data = "[49]"; or any digits inside brackets.

if(/\[\d+\]/.test(data)){
    //do something
}else{
    //default
}

Short answer: No, switch/case can't handle wildcard.

You should probably do some preprocessing/sanity checking before entering the switch, or simply discard it pletely since it's more appropriate for specific case scenarios rather than processing streamlined data. Regexp will serve you better here.

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