how I can write this condition in javascript(Reactjs)-CodePudding

i recently start a calculator project with react. I create the project and it works fine but i just wanna add a new feature to it. i wanna when i click on a operation symbol (like " ", "-", "*", "/") if i click one more time and the operation that exist before that be the same (for example 1234 ) when i click on " " or "-" my code don't add it to the code and replace it with the before operation and also do that to "/" and "*"

I also attach the repository link so you can see my calculator source code by yourself. the repository of project source code

CodePudding user response：

Please update handleClick function like below:

    const handleClick = (e) => {
        if(result.length && result.charAt(result.length-1) != e.target.name || result.length == 0)
        setResult(result.concat(e.target.name));   
}

CodePudding user response：

On your handleClick function simply check if the current character is an operator symbol (e.g: ' ','-','*','/') and the last character in the current result string is also an operator symbol. If they are both operator symbols simply do the following:

const handleClick = (e) => {
  if (result.length > 0 && (result[result.length - 1] === ' ' || result[result.length - 1] === '-' || result[result.length - 1] === '*' || result[result.length - 1] === '/') && (e.target.name === ' ' || e.target.name === '-' || e.target.name === '*' || e.target.name === '/')) {
    const newRes = result.slice(0, result.length - 1).concat(e.target.name);
    setResult(newRes);
  } else {
    setResult(result.concat(e.target.name));
  }
}