Hello i have a simple for loop what i want to combine the loop results into 1 string separated with a comma
String loc;
for(var q=0; q<2; q++){
userData = res;
loc = userData[q]['location'];
print(loc); //value in first loop is location A value in first second loop is location B i want to combine them on 1 string
}
If you want just append in String then
void main() {
String loc="";
List<String> locs = ["a","d","B","C"];
for(var q=0; q<2; q++){
loc = (loc.length>0? (loc+", ") : loc)+ (locs[q] ?? " ");
}
print(loc);
}
The traditional way would be to collect the strings into a string buffer, and manually add the comma:
var buffer = StringBuffer();
String separator = ""; // Avoid leading comma.
for (var data in userData) {
buffer..write(separator)..write(data["location"]);
separator = ",";
}
var loc = buffer.toString();
Another approach is to collect the values into a list and then use the join method:
var loc = [for (var data in userData) data["location"]].join(",");
That's probably more convenient in most cases, except when you need to do fancy computation on each element.
I have avoided using the for(;;) loop since you don't actually use the index for anything except accessing the user data. Then it's better to just for/in over the list elements directly.
Try ForEach
void main() {
List<String> places = ['New York', 'London', 'Berlin'];
String linearPlace = '';
places.forEach((thePlace) {
linearPlace = linearPlace + thePlace + ", ";
});
print(linearPlace);
//output: New York, London, Berlin,
// In case of Map
Map<String, String> countryCapitalsMap = {'Austria': 'Vienna',
'Armenia': 'Yerevan', 'India': 'Delhi'};
String countryWithCap = '';
countryCapitalsMap.forEach((key, value) {
countryWithCap = countryWithCap + key + ': ' + value + "\n";
});
print(countryWithCap);
// output:
// Austria: Vienna
// Armenia: Yerevan
// India: Delhi
}
