Difference between revisions of "Greater-than-or-equal"

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Greater-than-or-equal, >=, is an inequality operator to test whether the value on the left is greater than, or equal to, the value on the right.

Availability Present in all original versions of BBC BASIC.
Syntax BASIC I-V <num-var> = <numeric> >= <numeric>
<num-var> = <string> >= <string>
Token (hex) BASIC I-V 3E 3D (operator)
Description BASIC I-V Compares the values of the two operands and returns TRUE if they are equal, or if the left-hand operand is greater than the right, and FALSE otherwise.
Associated keywords =, <, >, <=, <>


>= evaluates the expressions on either side, and compares their values. If the values are equal, or if the value on the left is greater than the one on the right, it returns the Boolean value TRUE, otherwise it returns FALSE. It is usually used as the condition of an IF statement, but it is equally valid to assign the result to a variable.

The symbol is an ASCII substitute for ≥. The > comes first so that the = is not misinterpreted as an assignment statement (see =).

One numeric variable is greater than another if it is nearer to positive infinity. If both numbers are negative, the one with the smaller magnitude is greater. For the definition of 'greater-than' on strings, please see String collation.

It is not possible to daisy-chain (in)equality tests (for example IF bool% >= X = Y THEN ...), as the Group 5 operators do not associate. Please see = for more details.

Due to the numerical values of TRUE and FALSE in BBC BASIC, >= serves as a Boolean operator of material implication whose logical symbol is → :

A B A >= B

which, for these values, is identical to B OR NOT A.

-- beardo 23:24, 13 June 2007 (BST)