I have a very simple code that converts every letter to lower case and later sets upper case for every first letter using RegExp:
let quote = 'I dO nOT lIke gREen eGgS anD HAM';
let fixQuote = quote.toLocaleLowerCase('en-US');
let regex = /(^\w|\s\w)/g;
let fixedQuote = fixQuote.replace(regex, m => m.toUpperCase());
Can someone explain what does the arrow function m => m. does in this part?
I don't understand what m stands for here.
Thanks!
It is simply the internal variable of an anonymous function:
m is the parameter variable with value of regex.m.toUpperCase() is the return value.Essentially the same as:
function toUpperCase(m){
return m.toUpperCase();
}
In this case m is just a parameter to a function, so a variable name. You can imagine that function written like this:
function toUpperCase(m) {
return m.toUpperCase();
}
Every match found by your regex will be passed to the function as an argument. The variable m will hold that value.
function f(m){return m.toUpperCase();}