如何返回 Java 中的字符串列表？

Question

I want to return a list of strings when I call the method generateArrayList(2); It reminds me "Method does not exist or incorrect signature: void generateArrayList(Integer) from the type anon" Anyone help me, please: here is my class:

public class StringArrayTest {      
    public static List<String> generateArrayList(integer n){
        List<String> stringArray = new List<String>();
        for (integer i=0;i<n;i++){
            String str= 'Test'+String.valueOf(i);
            stringArray.add(str);
        }
        return stringArray;
    }
}

Answer 1

You have few compile time errors which needs to be corrected before it can work correctly.

1. integer : It will either be an int or an Integer . Use ArrayList
2. new List<String> : It's an interface. You can't instantiate an interface.
3. 'Test' : Single quotes is used for Character literal, for Strings use double quotes.
4. Also, there's no need of string.valueOf(i) .

Below, I have corrected all these errors. It should work now.

public static List<String> generateArrayList(int n){
    List<String> stringArray = new ArrayList<>();
    for (int i=0;i<n;i++){
        String str= "Test" + i;
        stringArray.add(str);
    }
    return stringArray;
}

Answer 2

In the beginning it's hard sometimes.

public static List<String> generateList(Integer n) {
    List<String> strings = new ArrayList<String>();
    for (Integer i = 0; i < n; i++) {
        String str = "Test" + String.valueOf(i);
        strings.add(str);
    }
    return strings;
}

Answer 3

The answer above is almost correct. you just need to put "SPACE" after "Test" here it is:

public static List<String> generateStringArray(Integer n){       
    List <String> strings = new List<String>();      
        for (Integer i = 0; i < n; i++){
            String str = 'Test ' + String.valueOf(i);
            strings.add(str);
        }
    return strings;
}}

also you can write it simplier:

public static List<String> generateStringArray(Integer n){       
    List <String> strings = new List<String>();      
        for (Integer i = 0; i < n; i++){
            strings.add('Test ' + i);               
        }
    return strings;
}}