CODEWITHSUNDEEP
javascriptangulartypescript
golden_code
golden_code

Reputation: 49

count number of occurrences of a variable in a child object in angular

I assigned a data that is returned from an API to a variable named todayData. There's a child object called meals which in it has a property name.

What I want to achieve is to count the number of occurrences in the name property of the meals object. For example, the meal Rice can have multiple occurrences in the data.

DATA

 [{"id":5,"referenceId":1189,"firstName":"Dan","lastName":"Daniels","orders":[{"id":109,"meals":[{"id":47,"name":"Fried Rice","description":"This is a  very sweet meal","image":"","mealType":"LUNCH","unitPrice":-20,"status":"ENABLED"}],"serveDate":"2019-07-11 00:00:00"}]}]

JS

let occurences = this.todayData.reduce(function (r, row) {
    r[row.orders.meals.name] = ++r[row.orders.meals.name] || 1;
    return r;
}, {});

let result = Object.keys(occurences).map(function (key) {
    return { meals: key, count: occurences[key] };
});
console.log(result);

Upvotes: 1

Views: 153

Answers (2)

Naveen Kumar V
Naveen Kumar V

Reputation: 2809

SOLUTION:

r[row.orders[0].meals[0].name] = ++r[row.orders[0].meals[0].name] || 1;

Since some properties are of Array type, index should be set.

EDIT 1:

Solution for data with multiple orders along with multiple meals. (Thanks to Bill Cheng for making me to consider general approach.)

let mealOccureneceCount = {};
  let occurences = this.todayData.forEach(user => {
    user.orders.forEach(order => {
      order.meals.forEach(meal => {
        mealOccureneceCount[meal.name] = (mealOccureneceCount[meal.name] || 0) + 1;
    });
  });
});
console.log(mealOccureneceCount);

Upvotes: 1

Bill Cheng
Bill Cheng

Reputation: 956

const occurences = this.todayData.reduce((r1, c1) => c1.orders.reduce((r2,c2) => c2.meals.reduce((r3,c3) => { r3[c3.name]= (r3[c3.name] || 0) + 1; return r3;}, r2), r1),{});

const result = Object.entries(occurences).map(([key, value]) => ({ meals: key, count: value }));

console.log(result);

Upvotes: 1

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