CODEWITHSUNDEEP
reactjsreact-state-management
Samarth Juneja
Samarth Juneja

Reputation: 896

How to avoid memory sharing of variables in react?

I am fetching some rows via an API and assigning the state variables like this

this.setState({
    rows: data,
    originalRows: data
})

Now I am using these state variables in a filter method where I change the number of rows based on filters.

let rows = this.state.rows
filterFunction(){
    //filter logic, editing the variable rows
}

The issue is, this also changes the value of this.state.originalRows How to avoid the change that state value?

Upvotes: 0

Views: 633

Answers (1)

Jimi Pajala
Jimi Pajala

Reputation: 2368

Various ways to achieve this.

// rest-spread operator copies values to new object
const obj = {...this.state.originalRows} 

// merges your values to an empty object which works same way
const obj2 = Object.assign({}, this.state.originalRows)

If you just write your code as following

const obj = this.state.originalRows

you just create reference to an original variable eg. pointer and change values with in original variable.

Upvotes: 1

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