CODEWITHSUNDEEP
javascriptreactjs
Mubi
Mubi

Reputation: 169

How Can I check if both Arrays inside this.state contains same value?

I have two Arrays , One contains the index number of correct answer correctAnswers

And userAnswers contain the index number of answer selected by the user

How Can I check if Both of them have a same value on the index , If yes then add +1 to the Total

    this.state = {
        correctAnswers: [], // [1, 2, 3, 1, 2, 1, 3, 3, 4, 3]
        userAnswers: [],    // [1, 3, 1, 2, 2, 1, 1, 3, 4, 3]
        Total: 0
    };

So in Above case Total should be Total =6

My attempt : 

const correctAnswers = this.state.correctAnswers;
    const userAnswers = this.state.userAnswers;

    compareAnswers() {
    for (var i = 0; i < correctAnswers.length; i++) {
        if (correctAnswers[i] === userAnswers[i]) {
            this.setState({ Total: +1 });
        } else console.log("ITS NOT A RIGHT ANSWER ");
    }
   }

Upvotes: 1

Views: 132

Answers (5)

Gorgamite
Gorgamite

Reputation: 237

Okay, since it's an array inside of an object, and the actual object has a this reference, we have to accommodate that.

  for(var i=0;i<this.state.correctAnswers.length;i++){
  if(this.state.correctAnswers[i] === this.state.userAnswers[i]){
    this.state.Total++;
  }
}

Using this method, we can dynamically compare both arrays. Hope this helps!

Upvotes: 3

Ele
Ele

Reputation: 33726

You can use forEach and a ternary condition:

state.Total += (c === state.correctAnswers[i] ? 1 : 0)


var state = {
  correctAnswers: [1, 2, 3, 1, 2, 1, 3, 3, 4, 3],
  userAnswers: [1, 3, 1, 2, 2, 1, 1, 3, 4, 3],
  Total: 0
};

state.userAnswers.forEach((c, i) => state.Total += (c === state.correctAnswers[i] ? 1 : 0));

console.log(state)
.as-console-wrapper { max-height: 100% !important; top: 0; }

Upvotes: 1

connexo
connexo

Reputation: 56754

Add a method to the object you already have:

let state = {
  correctAnswers: [1, 2, 3, 1, 2, 1, 3, 3, 4, 3],
  userAnswers: [1, 3, 1, 2, 2, 1, 1, 3, 4, 3],
  Total: 0,
  evalScore() {
    this.correctAnswers.forEach((answer, index) => {
        if (answer === this.userAnswers[index]) {
          this.Total++
        }
    })
  }
}

state.evalScore();
console.log(state.Total);

You can even use Total property for this and make it work like a computed property:

let state = {
  correctAnswers: [1, 2, 3, 1, 2, 1, 3, 3, 4, 3],
  userAnswers: [1, 3, 1, 2, 2, 1, 1, 3, 4, 3],
  Total() {
    // make sure both array have the same number of elements
    if(this.correctAnswers.length !== this.userAnswers.length) {
      return null;
    }
    let total = 0
    this.correctAnswers.forEach((answer, index) => {
        if (answer === this.userAnswers[index]) {
          total++
        }
    })
    return total
  }
}

console.log(state.Total());

Edit: Google Chrome Screenshot

Google Chrome Screenshot

Upvotes: 1

Anadi Sharma
Anadi Sharma

Reputation: 295

My attempt based on assumption that all the questions are mandatory and would be answered sequentially by the user:

compareAnswer() {
    // Addressing the best case i.e. when all user answers are correct
    if (JSON.stringify(this.state.correctAnswers) == JSON.stringify(this.state.userAnswers)) {
           this.setState({ Total: this.state.correctAnswers.length });
    } else {
           for (var i=0; i<this.state.userAnswers.length; i++) {
               if (this.state.correctAnswers[i] === this.state.userAnswers[i]) {
                  this.setState({ Total: this.state.Total++ });
               }
           }
    }
}

Upvotes: 1

CRice
CRice

Reputation: 32176

Your attempt looks good, except that it has a syntax error (you can't do Total: +1 like that). Instead you could use the functional setState syntax, which for your snippet would look like:

compareAnswers() {
    for (var i = 0; i < correctAnswers.length; i++) {
        if (correctAnswers[i] === userAnswers[i]) {
            this.setState(oldState => ({...oldState, Total: oldState.Total++}));
        } else console.log("ITS NOT A RIGHT ANSWER ");
    }
}

However, it would probably be better to batch all the sums and only set the state once when we're done, which would look like:

compareAnswers() {
    let newTotal = 0;
    for (var i = 0; i < correctAnswers.length; i++) {
        if (correctAnswers[i] === userAnswers[i]) {
            newTotal++;
        } else console.log("ITS NOT A RIGHT ANSWER ");
    }

    this.setState({Total: newTotal})
}

Upvotes: 1

Related Questions