Modify false values inside javascript object

Question

Using the JSON file I am trying to build a product list.

There are cases where products don't have data (was price) and in this case I dont want to display anything.

If "was_price" is false I want to modify its property to an empty string ' ' but I cannot print it even if in console.log works.

{
  "product_arr" : [
    {
      "name": "Example1",
      "price": 40,
      "was_price": false,
      "reviews": 80,
      "img": 1
    }, {
      "name": "Example2",
      "price": 250,
      "was_price": 300,
      "reviews": 98,
      "img": 2
    }
  ]
}

fetch('./data/product.json')
.then(function (response) {
    return response.json();
  })
  .then(function (data) {
    appendData(data);
    checkFalsePrice(data);
    })
    
  .catch(function (err) {
    console.log(err);
  });



function appendData(data) {
    const html = data.product_arr.map(item =>
       `<div class="product"> 
                <div class="row">
                    <div class="col-sm-3 child">
                        <div class="row">
                            <div class="media"><img src="img/${item.img}.jpg" /></div>
                        </div>
                        
                        <div class="row">
                            <div class="product-title">${item.name}</div>
                        </div>

                        <div class="row">
                            <div class="price"> £${item.price/100}</div>
                        </div>

                        <div class="row">
                            <div class="was-price"><span>Was</span> <span>${item.was_price/100}</span></div>
                        </div>

                        <div class="row">
                            <div class="reviews">${item.reviews}% Reviews Score</div>
                        </div>

                        
                    </div>
                </div>
           </div>`)
  document.getElementById("content").innerHTML = html.join("")

But return doesn't work

function checkFalsePrice(data) {
    data.product_arr.map(function (arr) {
        let wasPrice = arr.was_price;
            if(wasPrice === false) {
                return wasPrice.innerHTML = '';
            } else {
                return wasPrice;
            }
    })
}

<div id="content"></div>

Answer 1

dont use checkFalsePrice just try this

<div class="row">
   <div class="was-price"><span>Was</span> <span>${item.was_price/100 || ''}</span</div>
</div>