Javascript – Possible to use Math.min to get second smallest number from array

javascript

I am using Math.min to get the smallest number out of an array of numbers. However, I also need to get the second smallest number as well. Wondering if there is a way to do this using Math.min as well, otherwise looking for the best way to get this number.

Here's what I have:

var arr = [15, 37, 9, 21, 55];
var min = Math.min.apply(null, arr.filter(Boolean));
var secondMin; // Get second smallest number from array here

console.log('Smallest number: ' + min);
console.log('Second smallest number: ' + secondMin);

Best Answer

I see you are using Array.filter (but why?) on your first min. So, if we are using ES6 features you can find the second lowest value by first removing min from the array.

var secondMin = Math.min.apply(null, arr.filter(n => n != min));

edit: for clarity, unless you are doing something very clever with Array.filter(Boolean) while calculating the first min, you should just pass it the array without filtering:

var min = Math.min.apply(null, arr);

Related Solutions

Javascript – the best way to add options to a select from a JavaScript object with jQuery

The same as other answers, in a jQuery fashion:

$.each(selectValues, function(key, value) {   
     $('#mySelect')
         .append($("<option></option>")
                    .attr("value", key)
                    .text(value)); 
});

Javascript – Get the values from the “GET” parameters (JavaScript)

JavaScript itself has nothing built in for handling query string parameters.

Code running in a (modern) browser you can use the URL object (which is part of the APIs provided by browsers to JS):

var url_string = "http://www.example.com/t.html?a=1&b=3&c=m2-m3-m4-m5"; //window.location.href
var url = new URL(url_string);
var c = url.searchParams.get("c");
console.log(c);

For older browsers (including Internet Explorer), you can use this polyfill or the code from the original version of this answer that predates URL:

You could access location.search, which would give you from the ? character on to the end of the URL or the start of the fragment identifier (#foo), whichever comes first.

Then you can parse it with this:

function parse_query_string(query) {
  var vars = query.split("&");
  var query_string = {};
  for (var i = 0; i < vars.length; i++) {
    var pair = vars[i].split("=");
    var key = decodeURIComponent(pair[0]);
    var value = decodeURIComponent(pair[1]);
    // If first entry with this name
    if (typeof query_string[key] === "undefined") {
      query_string[key] = decodeURIComponent(value);
      // If second entry with this name
    } else if (typeof query_string[key] === "string") {
      var arr = [query_string[key], decodeURIComponent(value)];
      query_string[key] = arr;
      // If third or later entry with this name
    } else {
      query_string[key].push(decodeURIComponent(value));
    }
  }
  return query_string;
}

var query_string = "a=1&b=3&c=m2-m3-m4-m5";
var parsed_qs = parse_query_string(query_string);
console.log(parsed_qs.c);

You can get the query string from the URL of the current page with:

var query = window.location.search.substring(1);
var qs = parse_query_string(query);

Best Answer

Related Solutions

Javascript – the best way to add options to a select from a JavaScript object with jQuery

Javascript – Get the values from the “GET” parameters (JavaScript)

Related Topic