title: Redux Remove one item from cart
body: <p>I've build an app in <code>react-native</code> and i'm using <code>react-redux</code> to store data in my cart. </p>
  
  <p>Currently when I add a product lets say apple to my cart. My cart will contain 1x apple and if I add the same product to my cart I will have 2x apple. </p>
  
  <hr>
  
  <p><strong>Problem</strong></p>
  
  <p>But if I try to remove 1x apple my cart removes all the apples in my cart.</p>
  
  <hr>
  
  <p><strong>Question</strong></p>
  
  <p>How can I remove the item in my cart by -1?</p>
  
  <p><strong>cartitems.js</strong></p>
  
  <pre><code>case 'REMOVE_FROM_CART':
              return state.filter(cartItem=&gt;cartItem.id !== 
                  action.payload.id )
  </code></pre>
  
  <p><strong>CartProducts.js component</strong></p>
  
  <pre><code>&lt;View key={products.index} style={styles.appels}&gt;
        &lt;View style={styles.iconContainer}&gt; 
             &lt;Icon name={products.item.icon} color="#DD016B" size={25} /&gt;
        &lt;/View&gt;
        &lt;View style={styles.text}&gt;
             &lt;Text style={styles.name}&gt;
                  {products.item.name}
             &lt;/Text&gt;
  
             &lt;Text style={styles.price}&gt;
                  € {products.item.price}
             &lt;/Text&gt;
      &lt;/View&gt;
      &lt;View style={styles.buttonContainer}&gt;
            &lt;TouchableOpacity onPress={() =&gt; this.props.onPress(products.item)} &gt; 
                &lt;Icon style={styles.button} name="ios-remove" color="white" size={25} /&gt;
             &lt;/TouchableOpacity&gt;
          &lt;/View&gt;
       &lt;/View&gt;
  </code></pre>
  
  <p><strong>CartScreen.js</strong></p>
  
  <pre><code>&lt;Products products={appels} onPress={this.props.addItemToCart}/&gt;
  </code></pre>
  
  <p><strong>CartScreen.js | handeling removing product from cart</strong></p>
  
  <pre><code>const mapDispatchToProps = (dispatch) =&gt;{
      return{
          removeItem:(product) =&gt; dispatch ({
              type:'REMOVE_FROM_CART' , payload: product
          })  
      }
  }
  </code></pre>