I want to call the setCount in the button to decrease number in react in this code-CodePudding

import{useState}from'react';

export default function App() {
        const[state,setState]=useState('mariam');
  
        const[count, setCount]= useState((num)=>{
          if (num>=0) {
            setCount(count-1)
          } else {
            setCount(0)
          }
        });
    

 
  return (
    <div>
      <p>{state}</p>
      <input onChange={(e)=> setState(e.target.value)} />

       <p>{count}</p>
       <button onClick={setCount} >click</button>
    </div>
  )
}

CodePudding user response：

const [count, setCount] = useState(0)

const decrease = () => {
    setCount(count => {
        return count = count - 1;
    })
}

return (
    <>
        <p>{count}</p>
        <input type="button" onClick={decrease}>Decrease</input>
    </>
);

CodePudding user response：

To prevent negative values you can add a simple if statement

const [count, setCount] = useState(0)

const decrease = () => {
    setCount(prevCount => {
        if (prevCount - 1 < 0) return prevCount;
        return prevCount - 1;
    })
}

return (
    <>
        <p>{count}</p>
        <input type="button" onClick={decrease}>Decrease</input>
    </>
);