Regular expression pattern matching for number,alphabetcic blocks

Question

Im having some strings like these

aa11b2s
abc1sff3
a1b1sdd2

etc.... i need to change these strings to these

aa 11 b 2 s
abc 1 sff 3
a 1 b 1 sdd 2

Simply saying..i need to add a space between each(number/alphabetic s) blocks

Answer 1

var str = 'aa11b2s'.replace(/([a-z]+|\d+)(?!$)/gi, '$1 ');

Answer 2

var str = 'aa11b2s';
console.log(str.replace(/([\d.]+)/g, ' $1 ').replace(/^ +| +$/g, ''));