如何获得包含值的字符串数组中每个字符串名称的最大值？

Question

How would you go about getting the highest number of each color in the following array?

var array = ["Black 1", "Black 4", "Green 2", "Green 8", "Green 6", "Green 3", "Yellow 2"]

The result array should be:

["Black 4", "Green 8", "Yellow 2"]

Any tips or guidance would be extremely appreciated.
I was thinking that each value would need to be split between the color and the number but it's not clicking to me how to follow through with that.

Answer 1

You could iterate through your array using .reduce() . As you mentioned, you can use .split() to separate the colour from the number. Once you have both components, you can destructure the array you get from splitting your string to obtain the colour and the number ( score ) into separate variables. Using .reduce() , you can map to a Map , which stores keys as being the colours, and values as being the max score. In order to get the max score, you can check if the Map already has a number for your colour (indicating it has already been seen), and if it does, grab the max between the current number ( score ) and the current number stored in the Map, otherwise, you can make the Map store the current number score by taking the max between -Infinity and the current score value:

 const array = ["Black 1", "Black 4", "Green 2", "Green 8", "Green 6", "Green 3", "Yellow 2"]; const res = Array.from(array.reduce((map, str) => { const [color, score] = str.split(" "); const maxScore = Math.max(map.get(color) ?? -Infinity, score); return map.set(color, maxScore); }, new Map), entry => entry.join(" ")); console.log(res);

Answer 2

here's my take:

var array = ["Black 1", "Black 4", "Green 2", "Green 8", "Green 6", "Green 3", "Yellow 2"];
const temp = {};
array.forEach(color => {
  const [name, value] = color.split(' ');
  temp[name] = Math.max(value, temp[name] || 0);
});
const result = Object.entries(temp).map(color => `${color[0]} ${color[1]}`);

Like you said, I split each string into its name and value. Then keep track of the maximums in an object (called temp here). And finally convert to an array.

Answer 3

A simple reduce would do the trick.

Like this (I am using a nested IIFE in this implementation.):

 var array = ["Black 1", "Black 4", "Green 2", "Green 8", "Green 6", "Green 3", "Yellow 2"] var result = array.reduce( (acc, cur) => (([k, v]) => ({...acc, [k]: Math.max(v, acc[k] || 0)}) )(cur.match(/(.*)(\\d+)/).slice(1)), // IIFE call {}) console.log(Object.entries(result).map(([k, v]) => `${k}${v}`))

Answer 4

You can first split the string and then using Map to store the largest number and then finally using spread syntax to get the final result.

 var array = [ "Black 1", "Black 4", "Green 2", "Green 8", "Green 6", "Green 3", "Yellow 2", ]; const mapObj = new Map(); array .map((s) => s.split(" ")) .forEach(([k, v]) => mapObj.set(k, Math.max(mapObj.get(k) ?? Number.MIN_SAFE_INTEGER, v)) ); const result = [...mapObj].map(([k, v]) => `${k} ${v}`); console.log(result);