[removed] natural sort of alphanumerical strings

Question

I\'m looking for the easiest way to sort an array that consists of numbers and text, and a combination of these.

E.g.

\'123asd\'
\'19asd\'
\'12345asd\'         


        

Answer 1

Imagine an 8 digit padding function that transforms:

• '123asd' -> '00000123asd'
• '19asd' -> '00000019asd'

We can used the padded strings to help us sort '19asd' to appear before '123asd'.

Use the regular expression /\d+/g to help find all the numbers that need to be padded:

str.replace(/\d+/g, pad)

The following demonstrates sorting using this technique:

var list = [
    '123asd',
    '19asd',
    '12345asd',
    'asd123',
    'asd12'
];

function pad(n) { return ("00000000" + n).substr(-8); }
function natural_expand(a) { return a.replace(/\d+/g, pad) };
function natural_compare(a, b) {
    return natural_expand(a).localeCompare(natural_expand(b));
}

console.log(list.map(natural_expand).sort()); // intermediate values
console.log(list.sort(natural_compare)); // result

The intermediate results show what the natural_expand() routine does and gives you an understanding of how the subsequent natural_compare routine will work:

[
  "00000019asd",
  "00000123asd",
  "00012345asd",
  "asd00000012",
  "asd00000123"
]

Outputs:

[
  "19asd",
  "123asd",
  "12345asd",
  "asd12",
  "asd123"
]