I can't assign array to string variable in flutter-CodePudding

 for (i = 0; i < arr1.length - 1; i  ) {
  msg  = arr1[i]   ",";
}
msg  = arr1[i];

I want to throw the data from the above array into a string variable named msg with a comma between them. But I am getting an error as below. How can I fix.

_TypeError (type 'String' is not a subtype of type 'num' of 'other')

CodePudding user response：

It depends of what type of data is store in the array. If integers, or whatever else, you need to tranform to a string, with the toString() method

So:

msg  = arr1[i].tostring()   ",";

If mixed types, you can check type with something like this:

if (arr1[i] is int) {
  msg  = arr1[i].tostring()   ",";
}

if (arr1[i] is bool) {
  if (arr1[i]) { 
    msg  = "1,";
  } else {
    msg  = "0,";
}
 // And so on...

CodePudding user response：

The error indicates that your arr1 are List<num>. The function on num does not take a String which are the error you are getting.

I would recommend doing the following for creating your String since it will automatically call toString() on your num element and does also make the code smaller:

for (i = 0; i < arr1.length - 1; i  ) {
  msg  = '${arr1[i]},';
}
msg  = '${arr1[i]}';