appReducer.js

/* Create A Reducer
 *
 * You need to create a reducer called "appReducer" that accepts two arguments:
 * - First, an array containing information about ice cream 
 * - Second, an object with a 'DELETE_FLAVOR' `type` key
 * (i.e., the object contains information to delete the flavor from the state)
 *
 * The action your reducer will receive will look like this:
 * { type: 'DELETE_FLAVOR', flavor: 'Vanilla' }
 *
 * And the initial state will look something like this (as such, refrain 
 * from passing in default values for any parameters!):
 * [{ flavor: 'Chocolate', count: 36 }, { flavor: 'Vanilla', count: 210 }];
*/

const DELETE_FLAVOR = 'DELETE_FLAVOR';
var  appReducer = function( state, action ){
    
    if ( action.type === DELETE_FLAVOR ){
        
        var newState = [];
        state.forEach(function(element){
           if (element.flavor!== action.flavor){
               newState.push(element);
           } 
        });
        return newState;
    }
    
    return state;
};


var iceCreams = [{ flavor: 'Chocolate', count: 36 }, { flavor: 'Vanilla', count: 210 }];
var action = { type: 'DELETE_FLAVOR', flavor: 'Vanilla' };

var st = appReducer(iceCreams, action);
console.log(st);

function appReducer(state, action) {
if (action.type === 'DELETE_FLAVOR') {
return (state.filter(item => item.flavor !== action.flavor))
}
return state;
}

thanks bro

This was really helpful!