How to replace List item value with certain condition? - list

Question

Example: List of List =
[
[4, 175.52, 00, 175.52, 175.52],
[3, 175.52, 01, 175.52, 175.52]
]
1 = A
2 = B
3 = C
4 = D
And
00 = AA
01 = BB
12 = CC
15 = DD
I know I can use for loop and replace example in first item like:
4 to D and 00 to AA
Expected result:
[
[D, 175.52, AA, 175.52, 175.52],
[C, 175.52, BB, 175.52, 175.52]
]
So, How to replace List item value with certain condition?

Answer 1

This is a weird question so I'm not sure if this is what you're looking for:
void main() {
List<List<num>> bigList = [
[4, 175.52, 00, 175.52, 175.52],
[3, 175.52, 01, 175.52, 175.52]
];
List<List<dynamic>> newBigList = [];
for (List<num> smallList in bigList) {
List<dynamic> newSmallList = [];
for (num number in smallList) {
switch (number) {
case 1:
newSmallList.add("A");
break;
case 2:
newSmallList.add("B");
break;
case 3:
newSmallList.add("C");
break;
case 4:
newSmallList.add("D");
break;
case 00:
newSmallList.add("AA");
break;
case 01:
newSmallList.add("BB");
break;
case 12:
newSmallList.add("CC");
break;
case 15:
newSmallList.add("DD");
break;
default:
newSmallList.add(number);
}
}
newBigList.add(newSmallList);
}
print(newBigList);
}
This prints:
[[D, 175.52, AA, 175.52, 175.52], [C, 175.52, A, 175.52, 175.52]]

Answer 2

My question was replace the first (item(0)) and third (item(2)) in the this list. [4, 175.52, 00, 175.52, 175.52]. above post #mans gave me the correct answer. Differences is that in his solution you can replace every item in list if it meets the certain condition. In my problem is similar but replace only 2 items. I use if else statement before switch condition to get what I need.
void main() {
List<List<dynamic>> bigList = [
[2, 175.52, 00, 175.52, 175.52],
[3, 175.52, 01, 175.52, 175.52]
];
List<List<dynamic>> newBigList = [];
for (List<dynamic> smallList in bigList) {
List<dynamic> newSmallList = [];
for (var number in smallList) {
if (number == smallList[0]) {
switch (number) {
case 1:
newSmallList.add("A");
break;
case 2:
newSmallList.add("B");
break;
case 3:
newSmallList.add("C");
break;
case 4:
newSmallList.add("D");
break;
default:
newSmallList.add(number);
}
} else if (number == smallList[2]) {
switch (number) {
case 00:
newSmallList.add("AA");
break;
case 01:
newSmallList.add("BB");
break;
case 12:
newSmallList.add("CC");
break;
case 15:
newSmallList.add("DD");
break;
default:
newSmallList.add(number);
}
} else {
newSmallList.add(number);
}
// if else
} // inner for
newBigList.add(newSmallList);
} // outer for
print(newBigList);
}