New to javascript and I'm having trouble counting the number of trues in an array of boolean values. I'm trying to use the reduce() function. Can someone tell me what I'm doing wrong?
//trying to count the number of true in an array myCount = [false,false,true,false,true].reduce(function(a,b){ return b?a++:a; },0); alert("myCount ="+ myCount); // this is always 0
The countTrue() method of Booleans Class in Guava Library is used to count the number of values that are true in the specified boolean values passed as the parameter. Parameters: This method accepts the boolean values among which the true values are to be count.
Python len() method enables us to find the total number of elements in the array/object. That is, it returns the count of the elements in the array/object.
Seems like your problem is solved already, but there are plenty of easier methods to do it.
Excellent one:
.filter(Boolean); // will keep every truthy value in an array
const arr = [true, false, true, false, true]; const count = arr.filter(Boolean).length; console.log(count);
const arr = [true, false, true, false, true]; const count = arr.filter((value) => value).length; console.log(count);
let myCounter = 0; [true, false, true, false, true].forEach(v => v ? myCounter++ : v); console.log(myCounter);
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