I have a code like this:

if (action == 'John' || action == 'John Beckham' || action == 'Henry John'){
     alert('true!');
}

How do I minimize this code?

Should work in IE7.

I have a code like this:

if (action == 'John' || action == 'John Beckham' || action == 'Henry John'){
     alert('true!');
}

How do I minimize this code?

Should work in IE7.

• javascript
• jquery

• It's hard to see where your stuck here. What did you try? Where are you struggling? – Alexander R Commented Feb 25, 2013 at 12:12
• 2 You could remove the spaces ;-) and use a variable a instead of action... – Uooo Commented Feb 25, 2013 at 12:16
• You original question text was more clear than the current phrasing. It provided an example of what you wanted to achieve, which was checking set membership instead of checking each possible value directly (action ∈ [a,b,c] instead of action == a || action == b ...) – Simen Echholt Commented Feb 25, 2013 at 12:20
• I've updated it, because action is always different but may consist of the same words in different direction. – Jasper Commented Feb 25, 2013 at 12:26

7 Answers 7

If "John" always appears, the simplest thing is:

if (action.toLowerCase().indexOf("john") !== -1) {
    // Do something
}

...but as your question has already changed the values against which you're checking action once, I hesitate to assume that. Also note that it will match "xxxjohnxxx", which may not be what you want.

Original suggestions (updated for new action values from your edit):

There are lots of ways, all shown using case insensitivity since you mentioned that in the ments:

String#indexOf:

if ("|john|john beckham|john henry|giggs john|scholes john|john messi|".indexOf("|" + action.toLowerCase() + "|") !== -1) {
    // Do something
}

Regular expressions:

if (/^(?:John|John Beckham|John Henry|Giggs John|Scholes John|John Messi)$/i.test(action)) {
    // Do something
}

Because you're just using the true/false result, I'm using test which just returns true/false, instead of exec which returns matching results. Both work in this case, but the browser may be able to ever-so-slightly optimize test (but then, regex is unlikely to be the best solution if your goal is the fastest result or the least memory use).

Or a switch:

switch (action.toLowerCase()) {
    case "john":
    case "john beckham":
    case "john henry":
    case "giggs john":
    case "scholes john":
    case "john messi":
        // Do something
}

Or an object lookup:

var actions = {
    "john":         true,
    "john beckham": true,
    "john henry":   true,
    "giggs john":   true,
    "scholes john": true,
    "john messi":   true
};

if (actions[action.toLowerCase()]) {
    // do something
}

(That also has the advantage of letting you say what to do — e.g., the true could be replaced with a function you call.)

Or (on an ES5-enabled environment or with an ES5 shim) Array#indexOf:

if (["john", "john beckham", "john henry", "giggs john", "scholes john", "john messi"].indexOf(action.toLowerCase()) !== -1 {
    // Do something
}

or since you use jQuery, you can avoid the shim on older browsers by using inArray:

if ($.inArray(action.toLowerCase(), ["john", "john beckham", "john henry", "giggs john", "scholes john", "john messi"]) !== -1) {
    // Do something
}

if using jquery, then you could do:

var arr = ['a','b','c','d','e','f','g'];
if( $.inArray(action, arr) !== -1 ) {
  alert("true");
}

Try this, it uses indexOf:

if (['a', 'b', 'c', 'd', 'e'].indexOf(action) > -1) {
  alert(true);
}

Update: If you want to support IE7 and below, use the answer to this question

If you're using jQuery, you can use $.inArray like this:

if ($.inArray(action, ['a','b','c','d') > -1) {
  alert(true);
}

UPDATE

You can also use a regexp with test (The group makes the regexp not match "John Langhammerer" / actions with extra chars to the ones to be matched):

if ((/^(John Langhammer|Piet Krauthammer|Some Guy)$/i).test(action)) {
  alert(true);
}

UPDATE: /i makes the regexp case insensitive.

Below is a solution which would have worked for one-char actions:

You can also use String.indexOf which is supported in IE7 (if your actions are all one char):

if ('abcde'.indexOf(action) > -1) {
  alert(true);
}

Make an array as below.

var newAry = array('a','b','c');

Now just check it as below.

$(function()
{
    var newAry = Array('a','b','c');
    if($.inArray(action,newAry)){ alert(action); }
});

Cross-browser solution:

if ( action in {'John':1, 'John Beckham':1, 'John Henry':1, 'Giggs John':1, 'Scholes John':1, 'John Messi':1 } ){
     alert('true!');
}

In addition of indexOf, you can also use conditional operator in Javascript.

names = ['John' , 
         'John Beckham', 
         'John Henry' , 
         'Giggs John' , 
         'Scholes John', 
         'John Messi'
];
names.indexOf(action) != -1? alert('True') : alert ('False');

And you want to do more then simple statement do like:

 names.indexOf(action) != -1? doSomethingOnTrue() : doSomethingOnFalse(); 

if('abcdefg'.indexOf(action) > -1){
    // action is one of 'abcdef'
}