javascript - Create array containing the single chars of a string. How does these regular expression work? -

i guess start example code:

var sentence = 'lorem ipsum dolor sit amet, consectetuer adipiscing elit.';  // makes array single chars of sentence elements. sentence = sentence.split('');   // makes multi-dimensional array.  var result = sentence.map(function(ch) {   // using /./ leads multi-dimensional array too.   //  each array contains 2 empty strings elements.   //  => ["", ""]   return ch.split(/. /);  });  result.foreach(function(item, i) {   console.log(item);  // [ ["l"], ["o"], ["r"] ... ]  }); 

the purpose clear me: it's making multi-dimensional array. each element got 1 char of sentence.

what don't understand regular expression used.

. stands 1 arbitrary character in regular expressions.

what's purpose of blank after dot ( . ) ?

moreover: if rid of blank , write /./ results arrays too. each array contains 2 empty strings ( "" ) .

that behaviour isn't clear me too.

can explain described regular expression behaviour?

like add: have seen code-snippet here ... https://davidwalsh.name/write-javascript-promises

at bottom of section "chaining".

"x".split(/. /) 

has same effect as

"x".split(/rabbit/) 

it collect part of string doesn't contain delimiter (=the whole string), , stops.

"x".split(/./) 

collects part doesn't match . (=an empty string), consumes delimiter (=x) , appends rest of string (which empty) result.