CSC141 Computer Science I Zhen Jiang Dept. of Computer Science West Chester University West Chester, PA 19383 zjiang@wcupa.edu

Table of Contents Introduction Plain text format printout Variable and its value type Operator Math.pow & Math.sqrt Combined assignment DecimalFormat Prefix/postfix increment

Welcome Code 2-1, page 27 Names Main { } and ( ) Println and print (Code 2-3, page 35) \n (Code 2-5, page 36), \t (Code 2-6, page 37), and table 2-2. // (not \\) , page 77

Variable Code 2-7, page 39 Type (declaration) Name, page 43 Begin with [a]-[Z], or _, or $ Contain only [a]-[Z], [0]-[9], _, and $ No keyword Case distinct Samples, table 2-4, page 43

Assignment Assignment Left is a single variable Right is a legal expression Initialization, page 52 Value of variable and execution time line, page 53

Expression Operator, Code 2-8, page 40, Table 2-7, page 55 Precedence order, table 2-8, page 58 Prefix/postfix increment (decrement), page 193-196 n[x][y][pd].counter[type]++ Casting, page 66 17/3=? 17.0/3=? (double)17/3 = ? Types, Code 2-10, page 46 Sample, Code 2-18, page 60 10% off?

Advanced techniques Math.pow and Math.sqrt, page 62 Math.PI, page 70 Combined assignment, table 2-13, page 63 Scope, page 75

Keyboard Input Code 2-29, page 87

String Displaying message, Code 2-32, page 94 Input, converting a string to number, Code 2-33, page 97 Value of, page 582-583 Parse, table 2-18, page 96 Output converting a number to string, toString, page 603 DecimalFormat, Code 3-21,22,23,24, page 174-180

String (continue…) indexof, page 574 Substring, table 9-5, page 577 Concat, Table 9-6, page 581 Replace, Table 9-6, page 581 Length, Code 2-21, page 73 Sting.valueOf, table 9-7, page 583

Example String split “12.123456” => “12.123”