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I am having a problem with the following lines where car is a String array which has not been initialized/has no elements.
String car []; System.out.println(car.length); What is a possible solution?
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With the help of the length variable, we can obtain the size of the array. Examples: int size = arr[]. length; // length can be used // for int[], double[], String[] // to know the length of the arrays.
Using sizeof() function to Find Array Length in C++ The sizeof() operator in C++ returns the size of the passed variable or data in bytes. Similarly, it returns the total number of bytes required to store an array too.
To calculate the length of a string in Java, you can use an inbuilt length() method of the Java string class. In Java, strings are objects created using the string class and the length() method is a public member method of this class. So, any variable of type string can access this method using the . (dot) operator.
We can find the size of an array using the sizeof() operator as shown: // Finds size of arr[] and stores in 'size' int size = sizeof(arr)/sizeof(arr[0]);
Since car has not been initialized, it has no length, its value is null. However, the compiler won't even allow you to compile that code as is, throwing the following error: variable car might not have been initialized.
You need to initialize it first, and then you can use .length:
String car[] = new String[] { "BMW", "Bentley" }; System.out.println(car.length); If you need to initialize an empty array, you can use the following:
String car[] = new String[] { }; // or simply String car[] = { }; System.out.println(car.length); If you need to initialize it with a specific size, in order to fill certain positions, you can use the following:
String car[] = new String[3]; // initialize a String[] with length 3 System.out.println(car.length); // 3 car[0] = "BMW"; System.out.println(car.length); // 3 However, I'd recommend that you use a List instead, if you intend to add elements to it:
List<String> cars = new ArrayList<String>(); System.out.println(cars.size()); // 0 cars.add("BMW"); System.out.println(cars.size()); // 1 If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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