Java Learning--chapter II, "Java syntax"

Grammatical important points of knowledge

1. 8 Basic data types: Byte,short,int, long,double, Float,char,boolean (1,2,4,8,4,8,2byte).
2. The meaning of an explicit identifier, keyword, variable, constant.
3. Operators: Assignment operators, arithmetic operators, comparison operators, logical operators, bitwise operators, ternary operators (?). ：）。
4. Type conversions.
5. Code comments.

Process Control key points of knowledge

1. Conditional statement (if statement, switch statement (can use shape, character, string))
2. Loop statement (While,for,foreach)

Practice:

1. Print a diamond with a for loop

 Public Static voidMain (string[] args)
{         for(inti=1;i<5;i++)//draw above 4 lines        {             for(intj=4;j>i;j--)//Draw Spaces{System.out.print (" "); }             for(intk=1;k<=i*2-1;k++)//painting *{System.out.print ("*");        } System.out.println (); }                 for(inti=1;i<4;i++)//draw the following 3 lines        {             for(intj=i;j>0;j--)//Draw Spaces{System.out.print (" "); }             for(intk=5;k>=i*2-1;k--)//painting *{System.out.print ("*");        } System.out.println (); }    }

Java Learning--chapter II, "Java syntax"