How to initialize java array?

Arrays in Java language must be initialized before they can be used. The so-called initialization is to allocate memory space for the array elements of the array and attach an initial value to each array element.

Note: After the array is initialized, there is a default value for each element of the array in the memory space:

● Integer type of basic data type (byte, short, int, long ) The default value is 0;

● The default value of the floating point type (float, double) of the basic data type is 0.0;

● The default value of the character type (char) of the basic data type is ' \u0000';

●The default value of Boolean type of basic data type is false;

●The default value of reference type of type (class, array, interface, String) is null.

How to initialize a java array? Introduction to initialization methods

1. Static initialization: During initialization, the programmer explicitly specifies the initial value of each array element, and the system determines the length of the array;

arrayName = new type[]{element1,element2,element3...}

Example:

int[] intArr;
intArr = new int[]{1,2,3,4,5,9};

Simplified static initialization method:type[] arrayName = {element1, element2,element3...};

Example:

String[] strArr = {"张三","李四","王二麻"};

2. Dynamic initialization: The programmer specifies the length of the array during initialization, and the system initializes the default length of each array element. value.

arrayName = new type[length];

Example:

int[] price = new int[4];

Note: Do not use static initialization and dynamic initialization at the same time, that is, Do not initialize an array by specifying the length of the array or assigning an initial value to each array element.

Once the array is initialized, the space occupied by the array in memory will be fixed, so the length of the array cannot be changed.

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