How to make a dynamic variable in a for loop for javascript for a json return?

Question

The API I'm calling has a section of Ingredients I need to pull, and then push to the html page. They are listed as strIngredient1, strIngredient2, strIngredient3... Until 15. What I want to do is loop through each ingredient? I need some sort of dynamic variable I think. Totally not sure.

 for (var x = 1; x < 16; x++) { if ((drinkResponse.drinks[0].strIngredient + x) !== null) { $("#drinkOutput").append($("<p class='drinkData'>Drink Ingredient" + x + " : " + (drinkResponse.drinks[0].strIngredient + x) + "</p>")) } }

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>

This is the idea of what I want to do, but currently it returns NaN; when it should be returning a string.

JSON return:

 drinks[0] { dateModified: "2017-09-02 16:38:19" idDrink: "11224" strAlcoholic: "Alcoholic" strCategory: "Ordinary Drink" strCreativeCommonsConfirmed: "No" strDrink: "Casino Royale" strDrinkAlternate: null strDrinkDE: null strDrinkES: null strDrinkFR: null strDrinkThumb: "https://www.thecocktaildb.com/images/media/drink/3qpv121504366699.jpg" strDrinkZH-HANS: null strDrinkZH-HANT: null strGlass: "Whiskey sour glass" strIBA: null strIngredient1: "Gin" strIngredient2: "Lemon juice" strIngredient3: "Maraschino liqueur" strIngredient4: "Orange bitters" strIngredient5: "Egg yolk" strIngredient6: null strIngredient7: null strIngredient8: null strIngredient9: null strIngredient10: null strIngredient11: null strIngredient12: null strIngredient13: null strIngredient14: null strIngredient15: null strInstructions: "In a shaker half-filled with ice cubes, combine all of the ingredients. Shake well. Strain into a sour glass." strInstructionsDE: "In einem Shaker, der halb mit Eiswürfeln gefüllt ist, alle Zutaten vermengen. Gut schütteln. In ein Sour Glas abseihen." strInstructionsES: null strInstructionsFR: null strInstructionsZH-HANS: null strInstructionsZH-HANT: null strMeasure1: "2 oz " strMeasure2: "1/2 oz " strMeasure3: "1 tsp " strMeasure4: "1 dash " strMeasure5: "1 " strMeasure6: null strMeasure7: null strMeasure8: null strMeasure9: null strMeasure10: null strMeasure11: null strMeasure12: null strMeasure13: null strMeasure14: null strMeasure15: null strTags: null strVideo: null }

Answer 1

You are trying to append to the variable name with the value of x . You're close, but you need to use bracket notation rather than dot notation.

For example, if x is currently 5, you can get the value of strIngredient5 with drinkResponse.drinks[0]['strIngredient'+x] or drinkResponse.drinks[0][`strIngredient${x}`] .

As Lain pointed out, you can also use Object.keys to enumerate all of the keys on the object, then filter for only the keys which start with strIngredient :

// get all keys on the drink
const allKeys = Object.keys(drinkResponse.drinks[0]);

// now filter for only keys starting with `strIngredient`
const ingredients = allKeys.filter(key => key.startsWith('strIngredient'));

for (const i=0; i<ingredients.length; i++) {
    $("#drinkOutput").append($("<p class='drinkData'>Drink Ingredient" 
    + i + " : " + (drinkResponse.drinks[0][ingredients[i]]) + "</p>"))
}

Note that this may not preserve the order, but you can preserve the order by combining the first two examples:

for (const i=0; i<ingredients.length; i++) {
    $("#drinkOutput").append($("<p class='drinkData'>Drink Ingredient" 
    + i + " : " + (drinkResponse.drinks[0][`strIngredient${i}`]) + "</p>"))
}