To start learning Java programming from zero (five) - separator, identifier, the

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A, separator and pay attention to the use of


Two, identifier

The identifier is used to program variables, classes, symbol method named. The identifier for the Java language with a letter, underscore, the dollar sign at the beginning, may be followed by any number of letters, digits, underscores, the dollar sign. This letter is not confined to the 26 letters, and can include Chinese characters, Japanese characters, Korean characters. Specific usage see below:



For example: the correct identifier: Hello, ABC, $abc, name, _abc123  cannot correct identifier: 1abc,abc#,abc@

Three, the Java keyword

  Java language has some special uses of the words are called key (keyword), when defined identifier, don't let the identifiers and keywords, otherwise it will cause an error.

  All the keyword Java is small, TRUE, FALSE and NULL are not Java keyword.

Java consists of 48 words, 2 reserved words, 3 direct volume.

abstract assert boolean break byte case
catch char class continue default do
double else enum extends final finally
float for if implements import int
interface instanceof long native new package
private protected public return short static
strictfp super switch synchronized this throw
throws transient try void volatile while

2 reserved keywords: gotot and Const

3 direct variable: true,false,null


A: data type

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Posted by Beau at November 15, 2013 - 10:50 AM