--- id: 6352e93db104661305c5f658 title: Step 29 challengeType: 0 dashedName: step-29 --- # --description-- To calculate the occurrence you can use the following approach: ```js const numbersArr = [1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4]; const counts = {}; numbersArr.forEach((el) => { if (counts[el]) { counts[el] += 1; } else { counts[el] = 1; } }); ``` Check if the current number is already in the `counts` object. If it is, increment it by `1`. If it is not, set it to `1`. Resulting object. The keys are the numbers from the array and the values are the number of times each number appears in the list: ```js { 1: 3, 2: 3, 3: 3, 4: 3, 5: 2 } ``` For this step, start by declaring an empty `counts` object. Later on in the project, you will use this object to calculate the mode of the list of numbers. # --hints-- Your `getMode` function should have a `counts` variable. ```js assert.match(getMode.toString(), /counts\s*=/); ``` Your `counts` variable should be an empty object. ```js assert.match(getMode.toString(), /counts\s*=\s*\{\s*\}\s*;?/); ``` # --seed-- ## --seed-contents-- ```html
Enter a list of comma-separated numbers.
The mean of a list of numbers is the average, calculated by taking the sum of all numbers and dividing that by the count of numbers.
Mean:
The median of a list of numbers is the number that appears in the middle of the list, when sorted from least to greatest.
Median:
The mode of a list of numbers is the number that appears most often in the list.
Mode:
The range of a list of numbers is the difference between the largest and smallest numbers in the list.
Range:
The variance of a list of numbers measures how far the values are from the mean, on average.
Variance:
The standard deviation of a list of numbers is the square root of the variance.
Standard Deviation: