A collection of ways that I can go from number to Number in the hope to a) stop reinventing the wheel and b) see how many ways I can skin this problem.

Examples

'number'.split('').map(_ => _.charCodeAt(0)).map((_, i) => i === 0 ? _ - 32 : _).map(String.fromCharCode).join('')

'number'.split('').map((_, i) => _[`to${i === 0 ? 'Upper' : 'Lower'}Case`]()).join('')

This one is kind of silly and also potentially loses any capitalisation that already exists.

'number'.toUpperCase().split('').reduce((_, n) => _ + n.toLowerCase())

'number'.split('').reduce((_, n, i) => _ + (i ? n : n.toUpperCase()), '')

new TextEncoder().encode('number').map((_, i) => i ? _ : _ ^ 0x20).reduce((_, n) => _ + String.fromCharCode(n), '');

new TextEncoder().encode('number').reduce((_, n, i) => _ + String.fromCharCode(i ? n : n ^ 0x20), '');

(([a,...r])=>[a.toUpperCase(),...r].join(''))('number') // via twitter https://twitter.com/jamesseanwright/status/1071048376874094595

(n=>n[0].toUpperCase()+n.slice(1))('number')

(([n])=>n[0].toUpperCase()+n.slice(1))`number`

Random side effect discoveries. In asking: could I run a binary mask over the text (that is to XOR 32 - which would flip the first letter case)...

Drafts may be incomplete or entirely abandoned, so please forgive me. If you find an issue with a draft, or would like to see me write about something specifically, please try raising an issue.