I want my features to change every time I hit checkbox. I’ve added event listenter to a change. I supposed I would go this statement (as I stated that the ‘zero’ value is [0]) if (currentValue.length == 1) { feature.set('number', data_languages[language][index]); feature.changed() }
Then it was supposed to go ‘else’ statement (as any data in my variable data_languages[language][index] is an array of 4 elements). But I keep going the ‘if’ statement.

Here is the code:

input.addEventListener('change', function () {
        console.log(vectorLayer.getSource().getFeatures())
        if (input.checked) {
            var language = Object.keys(language_codes).find(key => language_codes[key] == input.id.split(':')[0]);
            var category = input.id.split(':')[1]
            if (category) {
                category = parseInt(category)
                // console.log(language, category)
                var features = vectorLayer.getSource().getFeatures();
                features.forEach(function (feature, index) {
                    var currentValue = feature.get('number');
                    if (currentValue.length == 1) {
                        feature.set('number', data_languages[language][index]);
                        feature.changed()
                    } else {
                        console.log(feature.get('number'))
                    }
                });
            }
        }
    });

I’m just exploring Openlayers and some things seem quite difficult to understand. I hope anyone can help me figure out what I am doing wrong here.