1const [prevState, setState] = React.useState([]);
2
3setState(prevState => [...prevState, 'somedata'] );

1const Component = (props) => {
2    const {receiveAmount, sendAmount } = props
3
4// declare usePrevious hook
5    const usePrevious = (value) => {
6      const ref = useRef();
7      useEffect(() => {
8        ref.current = value;
9      });
10      return ref.current;
11    }    
12    
13// call usePrevious hook on component state variables to store previousState
14    const prevAmount = usePrevious({receiveAmount, sendAmount});
15  
16  	// useEffect hook to detect change of state variables
17    useEffect(() => {
18        if(prevAmount.receiveAmount !== receiveAmount) {
19
20         // process here
21        }
22        if(prevAmount.sendAmount !== sendAmount) {
23
24         // process here
25        }
26    }, [receiveAmount, sendAmount])
27}

1import React, { useState } from "react";
2import ReactDOM from "react-dom";
3
4function Counter() {
5  const [count, setCount] = useState(0);
6
7  return (
8    <div>
9      <h1>{count}</h1>
10      <button onClick={() => setTimeout(() => setCount(count + 1), 2000)}>
11        Delayed Counter (basic)
12      </button>
13      <button onClick={() => setTimeout(() => setCount(x => x + 1), 2000)}>
14        Delayed Counter (functional)
15      </button>
16      <button onClick={() => setCount(count + 1)}>Immediate Counter</button>
17    </div>
18  );
19}
20
21const rootElement = document.getElementById("root");
22ReactDOM.render(<Counter />, rootElement);
23