Answer by Just code for How To delete object Array in objects state react

You have 2 issues in your code

1) You are not returning the new state when you are inside the state,

 this.setState(prevState => {      return {

here you are actually returning the new state.

so, your code should look like this

this.setState(prevState => {      return {        ...prevState, storeData: prevState.storeData.map(store => {                    if (store.code == storeCode) {            return {              ...store,              saveProducts: [                ...store.saveProducts.filter(product => product.id !== saveProductsId)              ]            };          } else {            return store;          }        })      }    })

2) You are comparing ...store.saveProducts.filter(product => product !== saveProductsId) here you need product.id instead of product

demo