reactjs - React - map a list in state does not properly affect the UI -


i have list in state of parent component:

this.state = {     productsform: [], }

and perform map on list , call child component:

    renderproducts() {     const result = this.state.productsform.map((value, index) => (       <productform         index={index}         onchange={(name, form, strength) => {           const productsform = this.state.productsform;           productsform[index] = { name, form, strength };           this.setstate({ productsform });         }}         onremove={(id) => {           const filtered = this.state.productsform.filter((_, i) => !== id);           this.setstate({ productsform: filtered });         }}       />     ));     return result;    }

in child component have remove button returns "id" of parent:

<floatingactionbutton onclick={() => { onremove(this.state.id); }} >

it works , remove child parent component, in ui, (i mean html page in browser) there problem. when ever remove child lower index, although removed state, remains in ui!

i think there problem in "index" or in code. have recommendation me fix issue?

you forgot add key attribute each productform component. way, react knows components have been changed. 

<productform key={index} ... />

it's better if use product's id key instead of index.


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