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[{'break_time':'09:00'},{' break_time ':'09:00'},{' break_time ':'09:00'},{' break_time ':'10:00'},{' break_time ':'10:00'},{' break_time ':'15:00'},{' break_time ':'09:00'}] how do I get the number of break_time and number of 09:00,10:00 and 15:00 in javascript? Keep getting TypeError: ret3.forEach/filter is not a function

DennisKip
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  • Possible duplicate of [Counting the occurrences / frequency of array elements](https://stackoverflow.com/questions/5667888/counting-the-occurrences-frequency-of-array-elements) – salvatore Feb 02 '19 at 07:09

2 Answers2

0

You can create a object and increase the count for each matches and get a final object with key as a time value and value as a count of that time:

var arr = [{
  'break_time': '09:00'
}, {
  'break_time': '09:00'
}, {
  'break_time': '09:00'
}, {
  'break_time': '10:00'
}, {
  'break_time': '10:00'
}, {
  'break_time': '15:00'
}, {
  'break_time': '09:00'
}];
var obj = {};
arr.forEach((arrObj) => {
  if(obj[arrObj.break_time]){
    obj[arrObj.break_time]++;
  } else {
    obj[arrObj.break_time] = 1;
  }
});
console.log(obj);
Ankit Agarwal
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0

Using a quasi-functional approach, you can write







var arr = [{'break_time':'09:00'},{'break_time':'09:00'},{'break_time':'09:00'},{'break_time':'10:00'},{'break_time':'10:00'},{'break_time':'15:00'},{'break_time':'09:00'}]
const breakCount = arr.filter(function(it) { return it.break_time }).length
const countByValue = arr.reduce(function(acc, curr) {
    acc[curr.break_time] = (acc[curr.break_time] || 0) + 1
    return acc
}, {})
console.log(breakCount)
console.log(countByValue)

EDITED

On ol versions of NodeJs or browsers you can rearrange Ankit Agarwal's answer as follows:

var arr = [{
  'break_time': '09:00'
}, {
  'break_time': '09:00'
}, {
  'break_time': '09:00'
}, {
  'break_time': '10:00'
}, {
  'break_time': '10:00'
}, {
  'break_time': '15:00'
}, {
  'break_time': '09:00'
}];
var obj = {};
for(var i = 0; i < arr.length; i++) {
  var arrObj = arr[i];
  if(obj[arrObj.break_time]){
    obj[arrObj.break_time]++;
  } else {
    obj[arrObj.break_time] = 1;
  }
}
console.log(obj);
Pietro Martinelli
  • 1,776
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  • So the thing is this when I try to implement any of this, I get the error ret3.filter TypeError: ret3.filter is not a function or ret3.forEach is not a function .. I am getting the data from mysql. – DennisKip Feb 02 '19 at 07:43
  • I can also get the in this format [["09:00"],["09:00"],["09:00"],["10:00"],["10:00"],["15:00"],["09:00"]] ..I am not sure what the format is exactly. kindly advice. – DennisKip Feb 02 '19 at 08:09
  • Ok, you are in the context of a NodeJs application, isn't it? In old versions of NodeJs `filter` and `forEach` methods were not available, so... you can rearrange Ankit Agarwal's answer as follows: ``` var arr = [...]; var obj = {}; for(var i = 0, i < arr.length; i++) { var arrObj = arr[i]; if(obj[arrObj.break_time]){ obj[arrObj.break_time]++; } else { obj[arrObj.break_time] = 1; } } console.log(obj); ``` – Pietro Martinelli Feb 02 '19 at 10:08
  • I updated my first answer including this old-style-javascript flavour... – Pietro Martinelli Feb 02 '19 at 10:14