Underscore _.findWhere contains backslash

Question

I'm trying to use _.findWhere to locate nodes that contain backslashes (they are indicating a 'sub folder' in an api). However i'm having an issue searching for a single backslash, and i'm not sure if this is just one of those things with the language that isn't easily possible. My function call currently looks like this:

        for(var i in data){
            if(
                _.findWhere(data, {name:'\\'})
            ) {
                console.log(data[i]);
                console.log('this');
            };
        }

and an example of the data:

[
    {
        "name": "QA",
        "matchedElements": [
            {
                "id": 285,
                "name": " exch2010"
            },
            {
                "id": 288,
                "name": "ad01"
            },
            {
                "id": 289,
                "name": "exchange01"
            },
            {
                "id": 290,
                "name": "ad02"
            }
        ]
    },
    {
        "name": "QA\\Stuff",
        "matchedElements": [
            {
                "id": 240,
                "name": "build-vmstudio-26"
            },
            {
                "id": 241,
                "name": "build-seleniumw"
            },
            {
                "id": 242,
                "name": "build-linux-02"
            },
            {
                "id": 250,
                "name": "build-rh5-x64"
            },
            {
                "id": 251,
                "name": "build-rh5-x86"
            },
            {
                "id": 563,
                "name": "build-linux-01"
            }
        ]
    },
    {
        "name": "PROD",
        "matchedElements": [
            {
                "id": 7,
                "name": "css-ora11sql2k8.uptimesoftware.com"
            },
            {
                "id": 8,
                "name": "css-sql2005.uptimesoftware.com"
            }
        ]
    }
]

Eventually the script will take the node with the double back slash, match it with a node of the same name and place it as a sub node to create a nested object.

I don't use underscore, but the docs suggest that it does an exact match. Also, I don't know why you're performing the same search over and over in a loop. — cookie monster, Mar 06 '14 at 19:51
@cookiemonster Thanks, appreciate the feedback on the script. — flashpunk, Mar 06 '14 at 20:11

score 2 · Accepted Answer · edited May 23 '17 at 12:10

2

findWhere is looking for an exact match - but none of your data is named only with the backslash. Instead, you would use find to get the first element with that name. However, the function you're actually looking for is _.some:

for (var i=0; i<data.length; i++){
    if( _.some(data[i].matchedElements, function(element) {
            return /\\/.test(element.name);
    }) ) {
        console.log(data[i]);
    }
}

Also, do not use for in loops on arrays!

Actually, you don't seem to need that loop at all. If you want Underscore to find those elements in data whose .name contains a backslash, just use

var elements = _.filter(data, function(element) {
    return /\\/.test(element.name);
});
_.each(elements, function(el) {
    console.log(el);
});

or equivalent - completely without underscore - the loop structure that you already had:

for (var i=0; i<data.length; i++){
    if( /\\/.test(data[i].name) ) {
        console.log(data[i]);
    }
}

Instead of /\\/.test(x) you also could use x.indexOf("\\")!=-1.

edited May 23 '17 at 12:10

Community

1
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answered Mar 06 '14 at 19:56

Bergi

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The "QA\\Stuff" node contains the double back slash. I'm trying to get this loop to work, but it doesn't seem to return anything, im not sure why it needs to access the matchedElements. – flashpunk Mar 06 '14 at 20:22
That's a single, but escaped backslash… What exactly does not work, by "return" do you mean "log"? – Bergi Mar 06 '14 at 21:06
yeah, apologies, it does not log anything. – flashpunk Mar 06 '14 at 21:20
I think it has to do with the regex, it's not matching the back slash. – flashpunk Mar 06 '14 at 21:40
1

Ooops wait my code was searching the `matchedElements` of each item for an element with that name... – Bergi Mar 06 '14 at 21:58
thank you muchly, the vanilla Js way is much cleaner IMO. Thank you! – flashpunk Mar 06 '14 at 22:09

Underscore _.findWhere contains backslash

1 Answers1