_.toggle function

[cojack]

Hello,
Could you implement an toggle function? By toggle I mean something like this:

    var idx = _.indexOf(collection, item);
    if(idx !== -1) {
        collection.splice(idx, 1);
    } else {
        collection.push(item);
    }

Thanks in advance.

[jdalton]

Hi @cojack!

I think this is better suited as a mixin.

[steven-prybylynskyi]

Implemented nicely with _.partial

function toggler(collection, item) {
    const idx = _.indexOf(collection, item);
    if(idx !== -1) {
        collection.splice(idx, 1);
    } else {
        collection.push(item);
    }
}
 
const model = [1, 2, 3];
const toggle = _.partial(toggler, model)

toggle(1); // [2,3]
toggle(4); // [2,3,4]

[pie6k]

I find it quite common use case. Would be useful without mixins :)

[petekp]

One use case a _.toggle function would be well suited for is handling state for multiple choice fields, e.g. an example in React:

handleChange = (e: Event) => {
    const [...selectedOptions] = this.state.selectedOptions

    if (selectedOptions.includes(selectedValue)) {
      selectedOptions.splice(selectedOptions.indexOf(selectedValue), 1)
    } else {
      selectedOptions.push(selectedValue)
    }

    this.setState({
      selectedOptions,
    })
  }

could be written something like

handleChange = (e: Event) => {
    const [...selectedOptions] = this.state.selectedOptions

    this.setState({
      selectedOptions: _.toggle(e.target.value, selectedOptions)),
    })
  }

[Martian2Lee]

_.xor([1], [2]);
= [1, 2]

_.xor([1, 2], [2]);
= [1]

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.