title: Typescript casting to number worked but now is not
body: <p>Yesterday i was casting some strings to number and they were working, now they don't ( i even did a commit thinking that everything was ok) , i tried to cast in any other ways, but still get Nan, it looks like something is happening to the variable that i assign the values that i cast(because i print them in console.log, and they are being casted)... so what am i doing wrong?</p>
  
  <p>Here's the code:</p>
  
  <pre><code>  totalPrice: number;
    total: number;
  
  
  if (this.cart_articles) {
              for (let article of this.cart_articles) {
                this.totalPrice += parseFloat(article.price);
                console.log(this.totalPrice); 
        console.log(parseFloat(article.price));
  
  
              }
              this.total = this.totalPrice + (this.totalPrice * 0.18);
              this.iva = this.totalPrice * 0.18;
            }
  </code></pre>
  
  <p>So i get Nan on the variables total,totalPrice and iva. But where i use console.log to show the values before assigning them to the variables, they are ok. How can i solve this? Sorry, as you can see, im new at this.</p>