1、int a = integer . parse int(" 123 ")； Converting the string 123 into an integer is not actually a direct conversion into an integer, but a package type of an int, but the package type of an int can be automatically converted into an int type.

2. Besides, you can also convert strings into characters, floating-point and double-precision. ParsetDouble (" 123.5 "), enter Double in the java editor, and you will be prompted.

3.int's packaging types are integer, floating point and double precision. Their packaging types are all uppercase, and the packaging type of char is Character.