Object properties dynamic delete

Question

I am curious about an improved way to dynamically delete properties from a javascript object based on wildcards. Firstly, suppose I have the following object: ``` object = { checkbox_description_1 : 'Chatoyant', checkbox_description_2 : 'Desultory', random_property : 'Firefly is a great program', checkbox_mood_1 : 'Efflorescent', checkbox_description_3 : 'Ephemeral' } ``` Task Now, the end result is to have removed all properties under the guise of 'checkbox_description' and leave the rest of the object intact as shown: ``` object = { random_property : 'Firefly is a great program', checkbox_mood_1 : 'Efflorescent', } ``` My solution At present my solution involves jquery and the following code: ``` var strKeyToDelete = 'checkbox_description' /* Start looping through the object */ $.each(object, function(strKey, strValue) { /* Check if the key starts with the wildcard key to delete */ if(this.match("^"+strKey) == strKeyToDelete) { /* Kill... */ delete object[strKey]; }; }); ``` Issue S…

Accepted Answer

This is the bare minimum required:

```
function deleteFromObject(keyPart, obj){
    for (var k in obj){          // Loop through the object
        if(~k.indexOf(keyPart)){ // If the current key contains the string we're looking for
            delete obj[k];       // Delete obj[key];
        }
    }
}

var myObject = {
    checkbox_description_1 : 'Chatoyant',
    checkbox_description_2 : 'Desultory',
    random_property : 'Firefly is a great program',
    checkbox_mood_1 : 'Efflorescent',
    checkbox_description_3 : 'Ephemeral'
};
deleteFromObject('checkbox_description', myObject);
console.log(myObject);
// myObject is now: {random_property: "Firefly is a great program", checkbox_mood_1: "Efflorescent"};
```

So that's pretty close to the jQuery function you have. (Though a little faster, considering it doesn't use jQuery, and `indexOf` instead of `match`)

So, what's with the `~` before `indexOf`?

`indexOf` returns a integer value: `-1` if the string is not found, and a index, starting from `0`, if it is found. (So always a positive integer if found) `~` is a bitwise `NOT`, that inverts this output. As it happens to be, the inverted output of `indexOf` is just what we need to indicate "found" or "not found".

`~-1` becomes `0`, a false-ish value. `~x`, where `x` is `0` or postitive, becomes `-(x+1)`, a true-ish value.

This way, `~string.indexOf('needle')` acts like `string.contains('needle')`, a function that we don't have in JavaScript.

Additionally, you could add a double boolean not (`!!`) in front of the `~`, to convert the true-ish or false-ish output to a real true / false, but that's not necessary in JavaScript. Functionally, `~string.indexOf('needle')` and `!!~string.indexOf('needle')` are equal.

In case you specifically need the key to begin with the needle, replace the:

```
~k.indexOf(keyPart)
```

With:

```
k.indexOf(keyPart) === 0
```

Object properties dynamic delete

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