Java字符串数组长度错误

Question

I'm a beginner in Java and practicing to code by myself. I'm using a book to teach me how to code and I'm stuck on a project where it includes creating a String array and determining its length. Here's my sample work. It's a simple baby name suggestion program.

public class BabyName {
    public static void main(String[] args) {
        String[] nameListOne = {"Alvin", "Elmer", "Angel", "Michael", "Tim", "Jude", "Gabriel", "Raphael", "John", "Smith", "Carl", "Mike"};
        String[] nameListTwo = {"", "Mark", "Posh", "Jake", "Cloud", "Star", "Ben", "Sam", "Kim", "Mark", "Simeon", "Louie", "Nat", "Matt", ""};

        int nameOneLength = nameListOne.Length;
        int nameTwoLength = nameListTwo.Length;

        int rand1 = (int) (Math.random() * nameOneLength);
        int rand2 = (int) (Math.random() * nameTwoLength);

        String babyname = nameListOne[rand1] + " " + nameListTwo[rand2];

        System.out.println("Your suggested baby name is " + babyname);
    }
}

I then get this errors when I tried to compile it:

BabyName.java:6: error: cannot find symbol
                int nameOneLength = nameListOne.Length;
                                               ^
  symbol:   variable Length
  location: variable nameListOne of type String[]
BabyName.java:7: error: cannot find symbol
                int nameTwoLength = nameListTwo.Length;
                                               ^
  symbol:   variable Length
  location: variable nameListTwo of type String[]
2 errors

I don't know what I did wrong here. I only followed what's written on the book.

Hope someone can help.

Answer 1

nameListOne.length长度应为小写

Answer 2

Java keywords are case sensitive. Use lowercase 'l' for 'length': nameListOne.length

Answer 3

It should be:

int nameOneLength = nameListOne.length;
int nameTwoLength = nameListTwo.length;

Answer 4

使用nameListOne.length Becoz Java区分大小写

Answer 5

Since you are a beginner, this would be helpful for you: Following are the naming conventions in Java ( a standard that should be (but not a must) followed)

• All the variable names begin with a lower case eg length and are in CamelCasing
• All Constants are all caps eg CONSTANT_LENGTH
• All Class names begin with Capital letter and are in CamelCasing, eg LengthType

So, with this information in mind, you can detect such issues earlier (by following conventions)

The issue with your code is "Length" is not a field, where as "length" is.

Remember; Java is Case-Sensitive.