University:
Georgia Southern University
Course:
ENGR1121 | Computing in Mechanical Engineering
Academic year:

2024
Views:

188

Pages:

4
Author:

Jalen W.

LOGICAL (BOOLEAN) EXPRESSIONS • comparison operators >, >=, <,<=, =, and <> • These operators are used to connect various operands, to form logical expressions (also known as Boolean expressions) that are either true or false. • Logical expressions can be combined using the logical functions AND, OR, and NOT. • The AND and OR functions each accept multiple arguments. • The NOT function reverses the value of its single argument. For example, the expression NOT(C1 > 0) will be false if the value in cell C1 exceeds 0 (i.e., it will be true only if the value in cell C1 is not greater than 0). MOD function • Some logical expressions involve use of the MOD function, which can be written as MOD(C1, C2). This function returns the remainder after dividing the value in cell C1 by the value in cell C2. • Thus, MOD(C1, 2) returns the remainder after the numerical value in cell C1 is divided by 2. If the numerical value in cell C1 is a positive integer, then the only possible remainders are 0 (if the value is even), or 1 (if the value is odd). • Now suppose we incorporate the MOD function into a logical expression by writing MOD(C1, 2) = 0. This expression will be true if the remainder is 0 (i.e., if the numerical value in cell C1 is even), or false if the remainder is 1 (if the numerical value in cell C1 is odd). Hence, we have a convenient way to determine whether a positive integer is even or odd. THE IF FUNCTION used to carry out branching operations • The IF function requires three arguments: a logical expression, followed by two values. • If the logical function is true, then the IF function returns the first value; if it is false, the function returns the second value. • For example, suppose cell B5 contains the formula =IF(C1 > 100, 50, C1/2) • If the value in cell C1 exceeds 100, the value 50 will be placed in cell B5. Otherwise if the value in cell C1 does not exceed 100, then half the quantity in cell C1 will be placed in cell B5. • To see what happens if the last two arguments are strings, suppose cell B5 contains the formula =IF(C1 > 100, "Too Big", "Ok") • If the value in cell C1 exceeds 100, "Too Big" will appear in cell B5.Page 91 Otherwise (if the value in cell C1 is less than or equal to 100), "Ok" will appear in cell B5. NESTED IF FUNCTIONS