如何使用 Javascript 从随机生成的数字数组中省略 0？

Question

I have done a code where it will generate 7 random numbers from 0 to 49.

HTML

<button id="btn_generate" onClick="getMyLuckyNumbers()">GENERATE NUMBERS</button>
<div id="display"></div>

JS

function getMyLuckyNumbers() {
for (var allNumbers=[],i=0;i<50;++i) allNumbers[i]=i;

function shuffle(array) {
  var tmp, current, top = array.length;
  if(top) while(--top) {
    current = Math.floor(Math.random() * (top + 1));
    tmp = array[current];
    array[current] = array[top];
    array[top] = tmp;
  }
  return array;
}

allNumbers = shuffle(allNumbers);

var luckyNumbers = "";
var g;

for (g = 0; g < 7; g++) {
    luckyNumbers += allNumbers[g] + "<br>";
}
document.getElementById("display").innerHTML = luckyNumbers;
}

I would like to know how I can omit 0?

I attempted two ways, but both failed.

Attempt 1:

Changed the i=0 to i=1 .

for (var allNumbers=[],i=1;i<50;++i) 
  allNumbers[i]=i;

This did omit 0 but when 0 was randomly supposed to appear, it shows as undefined.

Attempt 2:

I tried to do an if statement.

if(allNumbers != 0) {
  allNumbers = shuffle(allNumbers);
}

But this still displays 0 if it happens to be randomly generated.

So, how do I omit 0?

Answer 1

The issue with starting i from 1 is that the 0 th index will be empty, and so when accessed gives undefined .

So, if you want to avoid the number 0 , you can make i start at 1, but you would need to change the way you add numbers to your array. Instead of adding your numbers to your array by placing them at a specific index, you can .push() them to the end of your array each iteration like so:

//                      \/------ start at i = 1, the 1st number to be added to your array
for (var allNumbers=[],i=1;i<50;++i) 
  allNumbers.push(i);

This way, you will fill up your array with numbers from 1 to 49 which can them be shuffled.