Hi Friends đź‘‹,

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To pass parameters to a promise function in react native, create a parameter function and use promise in a function like the below example.

var getNameById = function (id) {
  return new Promise(function (resolve, reject) {
    // ...
  });
};

getNameById(3).then(function (res) {
  console.log(res);
});

// output: "Stuff worked"

Today, I’m going to show you How do I pass parameters to a promise function in react native, as above mentioned, I’m going to use the above-mentioned syntax to create and use a promise function with a parameter.

Let’s start today’s tutorial how do you pass parameters to a promise function in react native?

React native promise function with parameter example

Here we will create a parameter function and store it in a variable, in the function we will create a promise with a resolve & reject option where we will check if it is greater than 0 resolve promise or rejects.

import React, { useState, useEffect } from "react";
import { Text, View } from 'react-native';
export default function App() {
  const [str, setStr] = useState("");

  useEffect(() => {
    fetchFunction();
  }, []);

  const fetchFunction = async () => {
    let res = await getNameById(3);
    setStr(res);
  };

  const getNameById = (id) => {
    return new Promise((resolve, reject) => {
      if (id > 0) {
        resolve("Stuff worked!");
      } else {
        reject(Error("It broke"));
      }
    });
  };

  return (
    <View>
      <Text>{str}</Text>
    </View>
  );
}

In the above example, i have call promise function and store response in a state. printed state in a screen.

I hope it helps you, All the best đź‘Ť.

React Native, promise function example
React Native, promise function example

Try it yourself