使用JavaScript对数组进行函数排序

Question

I have to write a function, which sorts an array containing numbers and strings.
For example:

uSort([3,"2", 4,1,"a","c","b"])  // -> ["a","b","c",1,"2",3, 4].

This is what I've tried so far:

function uSort(arrayOfChars){
    var array = [];
    for (i = 0; i < arrayOfChars.length; i++) { 
        if (typeof(arrayOfChars[i]) === '' ){ 
            array.unshift(arrayOfChars[i]); }
        else { 
            array.push(arrayOfChars[i]);
        };   
    }; 
    return array.sort();
};

But the result is wrong:

uSort([3,"2", 4,1,"a","c","b"])  // -> [1,"2",3, 4,"a","b","c"].

I can't figure out what is wrong with my code right now.

Answer 1

One easy way to do that would be to just split the array into two arrays, one containing numbers and strings that are numbers, using isNaN , and one array containing everything else, then sort them and join them back together

function uSort(arrayOfChars){
    var numbs = arrayOfChars.filter(function(item) { return isNaN(item) });
    var chars = arrayOfChars.filter(function(item) { return !isNaN(item) });

    return numbs.sort().concat( chars.sort() );
};

FIDDLE

For better sorting of integers and special characters, you can add callbacks to the sorting

function uSort(arrayOfChars){
    var numbs = arrayOfChars.filter(function(item) { return !isNaN(item) });
    var chars = arrayOfChars.filter(function(item) { return isNaN(item) });

    return chars.sort(function(a, b) {
        return a.localeCompare(b);
    }).concat( numbs.sort(function(a, b) {
        return a == b ? 1 : a - b;
    }));
};

FIDDLE

Answer 2

You can use a custom comparator function which checks if the arguments are numeric with isNaN and then uses numerical or lexicographic sort:

[3, "2", 4, 1, "a", "c", "b"].sort(function(a,b) {
  if(isNaN(a) || isNaN(b)) {
    if(!isNaN(a)) return +1;              // Place numbers after strings
    if(!isNaN(b)) return -1;              // Place strings before numbers
    return a < b ? -1 : (a > b ? +1 : 0); // Sort strings lexicographically
  }
  return a - b;                           // Sort numbers numerically
}); // ["a", "b", "c", 1, "2", 3, 4]

Answer 3

Write your own custom sort method.

[3,"2", 4,1,"a","c","b"].sort( function (a,b) { 
    var sa = isNaN(a);
    var sb = isNaN(b);
    if(sa && sb) { //If both are strings, than compare
        return sa>sb; 
    } else if (!sa && !sb) {  //if both are numbers, convert to numbers and compare
        return Number(a) - Number(b);
    } else {  //if we have a number and a string, put the number last.
        return sa ? -1 : 1;
    }
});

Answer 4

It's normal to have numbers before letters (if this is your problem).

If you want to have letters before you have different ways.

One way is to order elements into two arrays (one for letters and one for numbers), then to merge them in the order you need.

Another way is to move the numbers at the end.

This is an example: alert((uSort([3,"2", 4,10,"a","c","b"]))) // -> ["a","b","c",1,"2",3, 4].

function uSort(arrayOfChars){
    var arrayNum = [];
    var arrayLet = [];
    for (i = 0; i < arrayOfChars.length; i++) { 
        if (typeof(arrayOfChars[i]) === '' ){ 
            array.unshift(arrayOfChars[i]); }
        else if (typeof(arrayOfChars[i]) === 'number' ){ 
            arrayNum.push(arrayOfChars[i]);
        } else {
            arrayLet.push(arrayOfChars[i]);
        }
    }; 

    if (arrayNum.size!=0 && arrayLet.size!=0) {
        arrayNum = arrayNum.sort(sortNumber);
        arrayNum.push();
        return arrayNum.concat(arrayLet.sort());
    } else if (arrayNum.size!=0) {
        return arrayNum.sort(sortNumber);
    } else {
        return arrayLet.sort();
    }


};

function sortNumber(a,b) {
    return a - b;
}