Is there a more efficient way to switch on each element of a string array?

Question

I have an array like var mya = ["someval1", "someotherval1", "someval2", "someval3"];, and I have a function that receives an object with a property set to one of those names.

It makes sense to iterate over the array and for each one check if I can find it in the array, like in a for statement. But it seems like a more efficient method would use a switch statement in this case, because the array is static and the task when I find the property is dependent on which property is found.

How do I do this with a switch array? Something like this pseudo code:

switch(mya.forEach) { 
    case "someval1": 
        alert("someval1"); 
        break; 
    ... 
    default: 
        alert("default"); 
        break; 
}

but this only calls once.

Both answers given are the code I already have — I guess there is no cleaner foreach formulation of switch.

score 5 · Accepted Answer · answered Dec 01 '13 at 14:18

5

for( var i=0; i<mya.length; i++ ){
    switch( mya[i]) { 
        case "someval1": 
            alert("someval1"); 
            break; 
        ... 
        default: 
            alert("default"); 
            break; 
    }
}

answered Dec 01 '13 at 14:18

sanchez

4,519
3
23
53

Cobra_fast was prettier, but yours was also correct and first. I'll give it in 8 minutes. – roberto tomás Dec 01 '13 at 14:23

score 1 · Answer 2 · answered Dec 01 '13 at 14:19

1

Because switch isn't foreach.

for (var i in mya)
{
    switch (mya[i])
    {
        ...
    }
}

answered Dec 01 '13 at 14:19

Cobra_Fast

15,671
8
57
102

David Thomas · Answer 3 · 2013-12-01T15:08:43.867

Given that you considered using forEach I'm assuming you're not too concerned with supporting older browsers, in which case it'd make far more sense to use Array.indexOf():

var mya = ["someval1", "someotherval1", "someval2", "someval3"],
    returnedFunctionValue = returnRandomValue();

console.log('Searching for: "' + returnedFunctionValue + '."');

if (mya.indexOf(returnedFunctionValue) > -1) {
    // the value held by the returnedFunctionValue variable is contained in the mya array
    console.log('"' + returnedFunctionValue + '" at array-index: ' + mya.indexOf(returnedFunctionValue));
}
else {
    // the value held by the returnedFunctionValue variable is not contained in the mya array
    console.log('"' + returnedFunctionValue + '" not held in the array');
}

Simple JS Fiddle demo.

Although you could, of course, use Array.prototype.forEach (in modern browsers):

var mya = ["someval1", "someotherval1", "someval2", "someval3"],
    returnedFunctionValue = returnRandomValue();

mya.forEach(function(a, b){
    if (a === returnedFunctionValue) {
        console.log('Found "' + returnedFunctionValue + '" at index ' + b);
    }
});

Simple JS Fiddle demo.

Is there a more efficient way to switch on each element of a string array?

3 Answers3