hooks and context react code example
Example 1: usecontext hook
import React, { useContext } from "react";
import ColorContext from "./colorcontex.ts";
const MyComponent = () => {
const colors = useContext(ColorContext);
return <div style={{ backgroundColor: colors.blue }}>...</div>;
};import React, { useContext } from "react";
const MyComponent = () => {
const colors = useContext(ColorContext);
return <div style={{ backgroundColor: colors.blue }}>...</div>;
};
Example 2: usereducer
function init(initialCount) { return {count: initialCount};}
function reducer(state, action) {
switch (action.type) {
case 'increment':
return {count: state.count + 1};
case 'decrement':
return {count: state.count - 1};
case 'reset': return init(action.payload); default:
throw new Error();
}
}
function Counter({initialCount}) {
const [state, dispatch] = useReducer(reducer, initialCount, init); return (
<>
Count: {state.count}
<button
onClick={() => dispatch({type: 'reset', payload: initialCount})}> Reset
</button>
<button onClick={() => dispatch({type: 'decrement'})}>-</button>
<button onClick={() => dispatch({type: 'increment'})}>+</button>
</>
);
}