Evaluate and give the output in 2 arrays

Question

const orderList = [["paul", "enter"],["jenny", "exit"],["paul", "exit"],["phil", "enter"],["shriya", "exit"],["shriya", "enter"],["shriya", "exit"],["paul", "enter"]["phil", "exit"],["Dan", "exit"],["Dan", "enter"]] Following the above order pls evaluate and give the output in 2 arrays, one for wrong entry and other for wrong exit. Order is important. Example: Paul has entered and exited which is correct. Again he has entered but didn't exit. So he comes in wrong exited array.

Answer 1

If I guessed it correctly then this is what you are looking for.

function check(orderList) {
    eventCount = {};
for(let i = 0; i < orderList.length; i++){
if(orderList[i]){
     let person = orderList[i][0];
    console.log(person, "--> ",orderList[i][1] );
    if(!eventCount.hasOwnProperty(person)){
            eventCount[person] = 0;
        }
    if(orderList[i][1] === "enter"){
        eventCount[person] = eventCount[person]+1;
    } else {
        eventCount[person] = eventCount[person]-1;
    }
}
    
}
let right = [];
let wrong = [];
for (const person in eventCount) {
  if(eventCount[person] === 0) {
      right.push(person);
  }else {
         wrong.push(person);
    }
}    
console.log("right -> ", right);
console.log("wrong -> ", wrong);
}

const orderList = [["paul", "enter"],
                    ["jenny", "exit"],
                    ["paul", "exit"],
                    ["phil", "enter"],
                    ["shriya", "exit"],
                    ["shriya", "enter"],
                    ["shriya", "exit"],
                    ["paul", "enter"],["phil", "exit"],["Dan", "exit"],["Dan", "enter"]];

check(orderList);