String comparison

String comparison is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.

You may see other such operations in the Basic Data Operations category, or:

Integer Operations
Arithmetic | Comparison

Boolean Operations
Bitwise | Logical

String Operations
Concatenation | Interpolation | Comparison | Matching

Memory Operations
Pointers & references | Addresses

The task is to demonstrate how to compare two strings from within the language and how to achieve a lexical comparison. The task should demonstrate:

• Comparison of strings for equality
• Comparison of strings for inequality
• Comparison of strings for one being lexically lower than the other
• Comparison of strings for one being lexically higher than the other
• Any other string comparative operators and features that the language provides.

See also:Integer comparison See also:Character matching

AWK

<lang awk>BEGIN {

 a="BALL"
 b="BELL"

 IF (a == b) { print "The strings are equal" }
 IF (a != b) { print "The strings are not equal" }
 IF (a > b) { print "The first string is lexically higher than the second" }
 IF (a < b) { print "The first string is lexically lower than the second" }
 IF (a >= b) { print "The first string is not lexically lower than the second" }
 IF (a <= b) { print "The first string is not lexically higher than the second" }

}</lang>

BASIC

<lang basic>10 LET "A$="BELL" 20 LET B$="BELT" 30 IF A$ = B$ THEN PRINT "THE STRINGS ARE EQUAL": REM TEST FOR EQUALITY 40 IF A$ <> B$ THEN PRINT "THE STRINGS ARE NOT EQUAL": REM TEST FOR INEQUALITY 50 IF A$ > B$ THEN PRINT A$;" IS LEXICALLY HIGHER THAN ";B$: REM TEST FOR LEXICALLY HIGHER 60 IF A$ < B$ THEN PRINT A$;" IS LEXICALLY LOWER THAN ";B$: REM TEST FOR LEXICALLY LOWER 70 IF A$ <= B$ THEN PRINT A$;" IS NOT LEXICALLY HIGHER THAN ";B$ 80 IF A$ >= B$ THEN PRINT A$;" IS NOT LEXICALLY LOWER THAN ";B$ 90 END</lang>

UNIX Shell

<lang sh>#!/bin/sh

A="Bell" B="Ball"

1. Traditional test command implementations test for equality and inequality
2. but do not have a lexical comparison facility

if [ $A = $B ] ; then

 ECHO 'The strings are equal"

fi if [ $A != $B ] ; then

 ECHO 'The strings are not equal"

fi</lang>