Proper loop syntax to remove object properties if value = x

Question

Say I have an object like so:

obj = {
    property1: "Prop 1 value",
    property2: "-",
    property3: "Prop 3 value"
    property4: "-"
}

If the property value equals "-" on a property I'd like to remove it from the object.

I've looked into for loops, but I don't even know if this is the right paradigm for working with an object.

Possible duplicate of [this](http://stackoverflow.com/questions/208105/how-to-remove-a-property-from-a-javascript-object). — Sotiris Kiritsis, Oct 15 '15 at 14:19
@user340764 Question was more related to proper looping mechanism than how to remove an object property. — Mdalz, Oct 15 '15 at 14:27

VisioN · Accepted Answer · 2015-10-15T14:20:54.963

6

The algorithm is pretty straightforward. You iterate all properties in the object, check if property value equals to "-" and delete it from the object.

for (var key in obj) {
    if (obj[key] === '-')
        delete obj[key];
}

edited Oct 15 '15 at 14:20

answered Oct 15 '15 at 14:19

VisioN

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Thanks, the "key in obj" was the syntax I was missing! – Mdalz Oct 15 '15 at 14:25

epascarello · Answer 2 · 2015-10-15T14:24:29.187

2

Simple for in loop with a comparison.

var obj = {
    property1: "Prop 1 value",
    property2: "-",
    property3: "Prop 3 value",
    property4: "-"
}

for (var prop in obj) {
    if (obj.hasOwnProperty(prop)) {
        if (obj[prop]==="-") {
            delete obj[prop];
        }
    }
}

Other option is Object.keys with a for loop

var obj = {
        property1: "Prop 1 value",
        property2: "-",
        property3: "Prop 3 value",
        property4: "-"
    }
Object.keys(obj).forEach(function(key) {
    if(obj[key]==="-") {
        delete obj[key];
    }
});

edited Oct 15 '15 at 14:24

answered Oct 15 '15 at 14:21

epascarello

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I don't think `hasOwnProperty` is really required here. Extending basic `Object` with values containing `"-"` looks really odd. – VisioN Oct 15 '15 at 14:23

Proper loop syntax to remove object properties if value = x

2 Answers2