javascript - Typescript strongly typed key value pair declaration -

i declare typescript interface such json structure:

{   404: function() { alert( "page not found" ); },   400 : function() {...}   }

the key number, , value function, know how declare interface in typescript such data constraints?

indexer

you can use numbers keys in javascript if use [] key access...

let's start desired code...

var x = {      404: function() { alert( "page not found" ); },      400 : function() { alert("...");}  };  x.404(); 

the last statement above (the call 404 function) error missing ; before statement, have use...

x[404](); 

while still type inference in typescript (var = x[404]; - a type () => void) - won't give auto-completion.

interface this:

interface httpcodealerts {    [index: number]: () => void; } 

with auto-completion

normally in javascript , typescript recommended use safer names. simplistically, need start them letter:

var x = {      e_404: function() { alert( "page not found" ); },      e_400 : function() { alert("...");}  };  x.e_404(); 

interface this:

interface httpcodealerts {     e_400: () => void;     e_404: () => void; } 

framework style

in languages, error used more this...

class httpcode {      static ok = { responsecode: 200, reasonphrase: 'okay' };     static notfound = { responsecode: 404, reasonphrase: 'not found' }; };  alert(httpcode.notfound.reasonphrase);