String Comparison Operators

Learn how to make alphabetic comparisons between Strings. They are useful for sorting and alphabetizing, among other things.

The String comparison operators

==
,
!=
,
>
,
<
,
>=
,
<=
, and the
equals()
and
equalsIgnoreCase()
methods allow you to make alphabetic comparisons between Strings. They're useful for sorting and alphabetizing, among other things.

The operator

==
and the method
equals()
perform identically. In other words,

1if (stringOne.equals(stringTwo)) {

is identical to

1if (stringOne ==stringTwo) {

The ">" (greater than) and "<" (less than) operators evaluate strings in alphabetical order, on the first character where the two differ. So, for example

"a" < "b"
and
"1" < "2"
, but
"999" > "1000"
because 9 comes after 1.

Caution: String comparison operators can be confusing when you're comparing numeric strings, because the numbers are treated as strings and not as numbers. If you need to compare numbers, compare them as ints, floats, or longs, and not as Strings.

Hardware Required

  • Arduino Board

Circuit

There is no circuit for this example, though your board must be connected to your computer via USB and the serial monitor window of the Arduino Software (IDE) should be open.

circuit

Code

Learn more

You can find more basic tutorials in the built-in examples section.

You can also explore the language reference, a detailed collection of the Arduino programming language.

Last revision 2015/08/11 by SM

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