How do I convert a string of numbers with commas in it to an integer and add them?

Question

I have an object called bondFilms with the following properties, for example "title", "year", and "gross": "272,828,282".

I want to loop through each item and add the gross values to get the total gross amount.

const bondFilms = [
{ "title" : "Skyfall", "year" : 2012, "actor" : "Daniel Craig", "gross" : "$1,108,561,008" },
{ "title" : "Thunderball", "year" : 1965, "actor" : "Sean Connery", "gross" : "$1,014,941,117" },
{ "title" : "Goldfinger", "year" : 1964, "actor" : "Sean Connery", "gross" : "$912,257,512" },
{ "title" : "Live and Let Die", "year" : 1973, "actor" : "Roger Moore", "gross" : "$825,110,761" },
{ "title" : "You Only Live Twice", "year" : 1967, "actor" : "Sean Connery", "gross" : "$756,544,419" },
{ "title" : "The Spy Who Loved Me", "year" : 1977, "actor" : "Roger Moore", "gross" : "$692,713,752" },
{ "title" : "Casino Royale", "year" : 2006, "actor" : "Daniel Craig", "gross" : "$669,789,482" },
{ "title" : "Moonraker", "year" : 1979, "actor" : "Roger Moore", "gross" : "$655,872,400" },
{ "title" : "Diamonds Are Forever", "year" : 1971, "actor" : "Sean Connery", "gross" : "$648,514,469" },
{ "title" : "Quantum of Solace", "year" : 2008, "actor" : "Daniel Craig", "gross" : "$622,246,378" },
{ "title" : "From Russia with Love", "year" : 1963, "actor" : "Sean Connery", "gross" : "$576,277,964" },
{ "title" : "Die Another Day", "year" : 2002, "actor" : "Pierce Brosnan", "gross" : "$543,639,638" },
{ "title" : "Goldeneye", "year" : 1995, "actor" : "Pierce Brosnan", "gross" : "$529,548,711" },
{ "title" : "On Her Majesty's Secret Service", "year" : 1969, "actor" : "George Lazenby", "gross" : "$505,899,782" },
{ "title" : "The World is Not Enough", "year" : 1999, "actor" : "Pierce Brosnan", "gross" : "$491,617,153" },
{ "title" : "For Your Eyes Only", "year" : 1981, "actor" : "Roger Moore", "gross" : "$486,468,881" },
{ "title" : "Tomorrow Never Dies", "year" : 1997, "actor" : "Pierce Brosnan", "gross" : "$478,946,402" },
{ "title" : "The Man with the Golden Gun", "year" : 1974, "actor" : "Roger Moore", "gross" : "$448,249,281" },
{ "title" : "Dr. No", "year" : 1962, "actor" : "Sean Connery", "gross" : "$440,759,072" },
{ "title" : "Octopussy", "year" : 1983, "actor" : "Roger Moore", "gross" : "$426,244,352" },
{ "title" : "The Living Daylights", "year" : 1987, "actor" : "Timothy Dalton", "gross" : "$381,088,866" },
{ "title" : "A View to a Kill", "year" : 1985, "actor" : "Roger Moore", "gross" : "$321,172,633" },
{ "title" : "License to Kill", "year" : 1989, "actor" : "Timothy Dalton", "gross" : "$285,157,191" }
];

let result = 0;
bondFilms.forEach((film)=>{
result = result + parseInt(film.gross.replace(",", ""))};
console.log(result);

However, for some reason I keep on getting NaN. Where did I go wrong?

Answer 1

A reproduction of the problem is:

console.log(parseInt("$42"));

That is, we need to account for the "$", because parseInt can't. We can do this by passing a regex to String#replace: /[$,]/g, which matches any literal "$" or "," character (we could also use something like /\D/g, being wary that we might accidentally chop leading negative signs). Note the g global flag.

Also, note that you're missing a closing ) on your filter function.

const bondFilms = [{ "title" : "Skyfall", "year" : 2012, "actor" : "Daniel Craig", "gross" : "$1,108,561,008" },{ "title" : "Thunderball", "year" : 1965, "actor" : "Sean Connery", "gross" : "$1,014,941,117" },{ "title" : "Goldfinger", "year" : 1964, "actor" : "Sean Connery", "gross" : "$912,257,512" },{ "title" : "Live and Let Die", "year" : 1973, "actor" : "Roger Moore", "gross" : "$825,110,761" },{ "title" : "You Only Live Twice", "year" : 1967, "actor" : "Sean Connery", "gross" : "$756,544,419" },{ "title" : "The Spy Who Loved Me", "year" : 1977, "actor" : "Roger Moore", "gross" : "$692,713,752" },{ "title" : "Casino Royale", "year" : 2006, "actor" : "Daniel Craig", "gross" : "$669,789,482" },{ "title" : "Moonraker", "year" : 1979, "actor" : "Roger Moore", "gross" : "$655,872,400" },{ "title" : "Diamonds Are Forever", "year" : 1971, "actor" : "Sean Connery", "gross" : "$648,514,469" },{ "title" : "Quantum of Solace", "year" : 2008, "actor" : "Daniel Craig", "gross" : "$622,246,378" },{ "title" : "From Russia with Love", "year" : 1963, "actor" : "Sean Connery", "gross" : "$576,277,964" },{ "title" : "Die Another Day", "year" : 2002, "actor" : "Pierce Brosnan", "gross" : "$543,639,638" },{ "title" : "Goldeneye", "year" : 1995, "actor" : "Pierce Brosnan", "gross" : "$529,548,711" },{ "title" : "On Her Majesty's Secret Service", "year" : 1969, "actor" : "George Lazenby", "gross" : "$505,899,782" },{ "title" : "The World is Not Enough", "year" : 1999, "actor" : "Pierce Brosnan", "gross" : "$491,617,153" },{ "title" : "For Your Eyes Only", "year" : 1981, "actor" : "Roger Moore", "gross" : "$486,468,881" },{ "title" : "Tomorrow Never Dies", "year" : 1997, "actor" : "Pierce Brosnan", "gross" : "$478,946,402" },{ "title" : "The Man with the Golden Gun", "year" : 1974, "actor" : "Roger Moore", "gross" : "$448,249,281" },{ "title" : "Dr. No", "year" : 1962, "actor" : "Sean Connery", "gross" : "$440,759,072" },{ "title" : "Octopussy", "year" : 1983, "actor" : "Roger Moore", "gross" : "$426,244,352" },{ "title" : "The Living Daylights", "year" : 1987, "actor" : "Timothy Dalton", "gross" : "$381,088,866" },{ "title" : "A View to a Kill", "year" : 1985, "actor" : "Roger Moore", "gross" : "$321,172,633" },{ "title" : "License to Kill", "year" : 1989, "actor" : "Timothy Dalton", "gross" : "$285,157,191" }];
let result = 0;
bondFilms.forEach((film) => {
  result = result + parseInt(film.gross.replace(/[$,]/g, ""))
});
console.log(result);

There are more succinct ways of achieving a reduction (transforming an array to a single value), for example Array#reduce, which accumulates a total using a callback function for each element in the array and an initial value for the accumulator. The unary + operator gives the same results as Number, performing a conversion without parseInt (results can be different, but edge cases are unlikely here).

const bondFilms = [{ "title" : "Skyfall", "year" : 2012, "actor" : "Daniel Craig", "gross" : "$1,108,561,008" },{ "title" : "Thunderball", "year" : 1965, "actor" : "Sean Connery", "gross" : "$1,014,941,117" },{ "title" : "Goldfinger", "year" : 1964, "actor" : "Sean Connery", "gross" : "$912,257,512" },{ "title" : "Live and Let Die", "year" : 1973, "actor" : "Roger Moore", "gross" : "$825,110,761" },{ "title" : "You Only Live Twice", "year" : 1967, "actor" : "Sean Connery", "gross" : "$756,544,419" },{ "title" : "The Spy Who Loved Me", "year" : 1977, "actor" : "Roger Moore", "gross" : "$692,713,752" },{ "title" : "Casino Royale", "year" : 2006, "actor" : "Daniel Craig", "gross" : "$669,789,482" },{ "title" : "Moonraker", "year" : 1979, "actor" : "Roger Moore", "gross" : "$655,872,400" },{ "title" : "Diamonds Are Forever", "year" : 1971, "actor" : "Sean Connery", "gross" : "$648,514,469" },{ "title" : "Quantum of Solace", "year" : 2008, "actor" : "Daniel Craig", "gross" : "$622,246,378" },{ "title" : "From Russia with Love", "year" : 1963, "actor" : "Sean Connery", "gross" : "$576,277,964" },{ "title" : "Die Another Day", "year" : 2002, "actor" : "Pierce Brosnan", "gross" : "$543,639,638" },{ "title" : "Goldeneye", "year" : 1995, "actor" : "Pierce Brosnan", "gross" : "$529,548,711" },{ "title" : "On Her Majesty's Secret Service", "year" : 1969, "actor" : "George Lazenby", "gross" : "$505,899,782" },{ "title" : "The World is Not Enough", "year" : 1999, "actor" : "Pierce Brosnan", "gross" : "$491,617,153" },{ "title" : "For Your Eyes Only", "year" : 1981, "actor" : "Roger Moore", "gross" : "$486,468,881" },{ "title" : "Tomorrow Never Dies", "year" : 1997, "actor" : "Pierce Brosnan", "gross" : "$478,946,402" },{ "title" : "The Man with the Golden Gun", "year" : 1974, "actor" : "Roger Moore", "gross" : "$448,249,281" },{ "title" : "Dr. No", "year" : 1962, "actor" : "Sean Connery", "gross" : "$440,759,072" },{ "title" : "Octopussy", "year" : 1983, "actor" : "Roger Moore", "gross" : "$426,244,352" },{ "title" : "The Living Daylights", "year" : 1987, "actor" : "Timothy Dalton", "gross" : "$381,088,866" },{ "title" : "A View to a Kill", "year" : 1985, "actor" : "Roger Moore", "gross" : "$321,172,633" },{ "title" : "License to Kill", "year" : 1989, "actor" : "Timothy Dalton", "gross" : "$285,157,191" }];

const result = bondFilms.reduce((a, e) => 
  a + +e.gross.replace(/[$,]/g, ""), 0)
;
console.log(result);