Javascript combinations enumeration (not fast)

comb=function(a,n){
  var ids=new Array(n).fill(0).map((i,ind)=>ind);
  var res=[];
  //console.log(indexes);
  var evs="";
  for(i in ids)
    evs+=`for(ids[${i}]=((ids[${i}-1]==null)?(-1):ids[${i}-1])+1;ids[${i}]<=a.length-n+${i};ids[${i}]++){\n`;
  evs+=`res.push(a.filter(    (ii,ind)=>(ids.indexOf(ind)!=-1)    ));\n`;
  evs+="}\n".repeat(n);
  console.log(evs);
  eval(evs);
  return (res);
}



alert(JSON.stringify(comb([1,2,3],2)));

Simple dialog / list dialog in javascript using jquery & bootstrap

(async ()=>{ alert2(await showlist("select number",[1,2,3,4,5])); })()


First, include jquery and bootstrap

WebUSB/Arduino on Windows 8 - How to make it work

Recently I'm playing with arduino and hoped to utilize the WebUSB API to enable cross-platform control over my arduino board. Here's some directions on how to get it work:

Outlines

• Get a board that is compatible: I used Arduino Leonardo
• Download ArduinoDroid for Android
• Download WebUSB library
• Upload your sketch to the board
• Install Zadig on your windows to replace the original Driver and let it work
  

Javascript Permutations Enumeration (not fast)

patt=function(arr){
if(arr.constructor.name!="Array")
  return [];
arr=arr.slice();
if(arr.length==1)
  return [arr];
else if(arr.length==2)
  return [arr,arr.slice().reverse()];
else
 {
  let sum=[];
  let el=arr.shift();
  let darr=patt(arr);
  for(var i in new Array(arr.length+1).fill(0))
    sum.push(...darr.map(item=>
      {
        let cp=item.slice();
        cp.splice(i,0,el);
        return cp;
      }));
  return sum;
 }
};



alert(JSON.stringify(patt([1,2,3])));

Webusb test

External library from
https://github.com/webusb/arduino

Arduino Control by Form Submit

訊息：setm
密碼：

A javascript analog of python's range

var range=(a,b,c)=>
  {
    if(!b) b=1;
    if(!c) c=1;
    let arr=new Array(Math.floor(Math.abs(a-b)/c)+1).fill(0);
    arr=arr.map((i,ind)=>(ind*(b-a)/(arr.length-1)+a));
    return arr;
  };






for(i of range(4,2)){alert(i);}