I have array with integer index
myarray[1]=val1
myarray[2]=val2
myarray[4]=val3
myarray[5]=val4
in this case myarray[0] and myarray[3] is undefined and
for (var i in myarray)
{
console.log(i)
}
output 1,2,4,5
I like to "remove" myarray[2] without shifting others members and that after delete also myarray[2] come to be undefined and output should be 1,4,5
I tred myarray.splice(2,1,undefined) but it's still output index 2
Stop stop!
First problem, while yes most things in js are objects, do not iterate over arrays with for in. "for ... in" is for object literals. Use a normal iterative loop for arrays.
Second, delete is intended to delete properties on objects. Again, arrays are objects but this isn't the right use of delete.
If you want to set the value of an array index to undefined, just assign it undefined.
myarray[2] = undefined;
Edit:
The reason you don't use for...in on an array is this:
var x = [1,2,3];
x.test = 'abc';
for(var i in x){
console.log(x[i]);
}
//1,2,3,abc
for(var i=0; i<x.length; i++){
console.log(x[i]);
}
//1,2,3
What Dmitry seems to be trying to do is only return indices that have values. Do it like this.
for(var i=0; i<myarray.length; i++){
if( myarray[i] !== undefined ){
console.log( myarray[i] );
}
}
Again, to set an index to undefined you shouldn't use delete. You can, but don't. Just do:
myarray[i] = undefined;
Hope this helps.
for..in are never undesirable though.
Use delete:
delete myarray[2];
delete myArray[2];
Use delete to remove an array index.
>> myArray[2]
undefined
And now you won't iterate over it with your for-in loop.
Also, for-in should only be used for iterating over object's properties. Use a regular for-loop when iterating over arrays.
myArray[2] = undefined;?