使用javascript中的sort方法对数组进行排序

Question

I have written this code but it isn't working . It's displaying the unsorted array as well as the button but when I click on the button nothing happens. I am new to javascript. What I know so far is that we can call functions using the onclick method by javascript. We can write functions as we write in c or c++ . That's what I think I have done here but it isn't showing the sorted array .

 var myarray = [4, 6, 2, 1, 9, ]; document.getElementById("demo").innerHTML = myarray; function sort(myarray) { var count = array.length - 1, swap, j, i; for (j = 0; j < count; j++) { for (i = 0; i < count; i++) { if (array[i] > myarray[i + 1]) { swap = myarray[i + 1]; myarray[i + 1] = myarray[i]; myarray[i] = swap; } } document.write(myarray); } } 

 <p>Click the button to sort the array.</p> <button onclick="sort()">Try it</button> <p id="demo"></p> 

Answer 1

The main problem is, to decide if a parameter should be set or not. If not, then use myarray for all operations. If you decide to use a parameter, then use only the parameter variable.

 var myarray = [4, 6, 2, 1, 9, ]; document.getElementById("demo").innerHTML = myarray; function sort() { // no need for a parameter var count = myarray.length - 1, // change it to myarray swap, j, i; for (j = 0; j < count; j++) { for (i = 0; i < count; i++) { if (myarray[i] > myarray[i + 1]) { // access only myarray swap = myarray[i + 1]; myarray[i + 1] = myarray[i]; myarray[i] = swap; } } } document.getElementById("demo").innerHTML = myarray; // return the sorted array } 

 <p>Click the button to sort the array.</p> <button onclick="sort()">Try it</button> <p id="demo"></p> 

Answer 2

 var myarray = [4, 6, 2, 1, 9]; document.getElementById("demo").innerHTML = myarray; function sort(myarray) { var count = myarray.length - 1, swap, j, i; for (j = 0; j < count; j++) { for (i = 0; i < count; i++) { if (myarray[i] > myarray[i + 1]) { swap = myarray[i + 1]; myarray[i + 1] = myarray[i]; myarray[i] = swap; } } } document.getElementById("result").innerHTML = myarray; } 

 <p>Click the button to sort the array.</p> <button onclick="sort(myarray)">Try it</button> <p id="demo"></p> <p id="result"></p> 

Answer 3

I found 2 problems with your code. The first is that you wrote array instead of myarray in 2 lines:

var count = array.length - 1,

and

if (array[i] > myarray[i + 1]) {

The second problem is that you didn't pass your array as argument, when calling the function, so:

<button onclick="sort()">Try it</button>

should be:

<button onclick="sort(myarray)">Try it</button>

Answer 4

Firstly you array definition has an extra , at the end. Next, you have made use of array and not myarray in the if statement.

Once you sort, you need to have a statement:

document.getElementById("demo").innerHTML = myarray;

Answer 5

You are using a variable 'array' which is not defined or known to the function. Moreover on buttonclick you are not passing any parameter to sort function. That's the reason you're getting an error.

var myarray = [4, 6, 2, 1, 9, ];

function sort(myarray) {
  var count = myarray.length - 1,
    swap,
    j,
    i;

  for (j = 0; j < count; j++) {
    for (i = 0; i < count; i++) {
      if (myarray[i] > myarray[i + 1]) {
        swap = myarray[i + 1];
        myarray[i + 1] = myarray[i];
        myarray[i] = swap;
      }
    }
    document.write(myarray);
  }
}

<p>Click the button to sort the array.</p>
<button onclick="sort(myarray)">Try it</button>
<p id="demo"></p>