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Last Class (sections 3.4 - 3.6). What is a variable? rules for naming variables garbage values strings, chars, boolean rules for naming variables Integer Variables example from book +, -, *. Data Types: Reals. A number that contains a decimal point can begin with a ‘+’ or a ‘-’
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Last Class (sections 3.4 - 3.6) • What is a variable? • rules for naming variables • garbage values • strings, chars, boolean • rules for naming variables • Integer Variables • example from book • +, -, *
Data Types: Reals • A number that contains a decimal point • can begin with a ‘+’ or a ‘-’ • must have digits on both sides of the decimal • cannot contain • commas • an embedded blank • non-numeric characters • a’+’ or a ‘-’ at the end of the value
Real Operators • +, - • *, / • operator precedence • PEMDAS
Integer Operators • +, - • * • DIV “integer division” • MOD “remainder operator” • operator precedence
Mixed mode • You can assign an integer value to a real variable. The compiler automatically converts the integer into a real (ie. 5 -> 5.0) • You cannot assign a real to an integer. • Mixed mode is when both integers and reals are on the right side of an expression (a real variable must be on the left side).
Section 3.11 • readln
Correcting syntax errors • Go over example in book