Conteúdo do Curso
Introduction to JavaScript
Introduction to JavaScript
Comparison Operations
Comparisons are used to define conditions, perform checks, and make decisions in JavaScript. These operations return a boolean value (true
or false
), which other operators use to determine certain actions.
Comparison Operators
JavaScript offers several comparison operators for comparing values:
- Equal to (
==
); - Strict Equal To (
===
); - Not Equal To (
!=
); - Strict Not Equal To (
!==
); - Greater Than (
>
); - Greater Than or Equal To (
>=
); - Less Than (
<
); - Less Than or Equal To (
<=
).
Equal and Not Equal
The Equal To operation (==
) returns true
if the first value equals the second value and false otherwise.
Conversely, the Not Equal To operation (!=
) returns true
if the values are unequal.
Example:
console.log("Equal to:"); console.log("5 == 5 is", 5 == 5); console.log("5 == 4 is", 5 == 4); console.log("5 == 4.99 is", 5 == 4.99); console.log("Not equal to:"); console.log("5 != 5 is", 5 != 5); console.log("5 != 4 is", 5 != 4); console.log("5 != 4.99 is", 5 != 4.99);
Note
The
=
operator is for assignment, while==
is for comparison. Be careful to distinguish them.
Strict comparison
Strict comparison checks the types of values and values. The Strict Equal To (===
) operator returns true
- if both the values and their types are the same, while !==
returns true
if they are different.
Example:
console.log("5 === 5 is", 5 === 5); console.log("5 === '5' is", 5 === '5'); console.log("5 == '5' is", 5 == '5'); console.log("5 !== 5 is", 5 !== 5); console.log("5 !== '5' is", 5 !== '5'); console.log("5 != '5' is", 5 != '5'); console.log("Type of 5 is", typeof(5)); console.log("Type of '5' is", typeof('5'));
Greater and Less
The Greater Than (>
) operator returns true
if the first value exceeds the second. Conversely, the Less Than (<
) operator returns true
if the first value is less than the second.
Example:
console.log("5 > 5 is", 5 > 5); console.log("5 > 4.99 is", 5 > 4.99); console.log("5 > 5.0000001 is", 5 > 5.0000001); console.log("5 < 5 is", 5 < 5); console.log("5 < 4.99 is", 5 < 4.99); console.log("5 < 5.0000001 is", 5 < 5.0000001);
Greater/Less Than or Equal to
The Greater Than or Equal To (>=
) and Less Than or Equal To (<=
) operators combine the corresponding comparison operators with Equal To (==
). They return true
if either of the conditions is satisfied.
console.log("5 >= 5 is", 5 >= 5); console.log("5 >= 4.99 is", 5 >= 4.99); console.log("5 >= 5.0000001 is", 5 >= 5.0000001); console.log("5 <= 5 is", 5 <= 5); console.log("5 <= 4.99 is", 5 <= 4.99); console.log("5 <= 5.0000001 is", 5 <= 5.0000001);
Note
The
>=
operator combines>
and==
, not===
. The<=
operator works similarly.
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