The inequality operator (!=
) checks whether its two operands are not equal, returning a Boolean result. Unlike the strict inequality operator, it attempts to convert and compare operands that are of different types.
x != y
The inequality operator checks whether its operands are not equal. It is the negation of the equality operator so the following two lines will always give the same result:
x != y !(x == y)
For details of the comparison algorithm, see the page for the equality operator.
Like the equality operator, the inequality operator will attempt to convert and compare operands of different types:
3 != "3"; // false
To prevent this, and require that different types are considered to be different, use the strict inequality operator instead:
3 !== "3"; // true
1 != 2; // true "hello" != "hola"; // true 1 != 1; // false "hello" != "hello"; // false
"1" != 1; // false 1 != "1"; // false 0 != false; // false 0 != null; // true 0 != undefined; // true 0 != !!null; // false, look at Logical NOT operator 0 != !!undefined; // false, look at Logical NOT operator null != undefined; // false const number1 = new Number(3); const number2 = new Number(3); number1 != 3; // false number1 != number2; // true
const object1 = {"key": "value"} const object2 = {"key": "value"}; object1 != object2 // true object2 != object2 // false
Desktop | ||||||
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Inequality (a != b ) |
1 | 12 | 1 | 3 | 3 | 1 |
Mobile | ||||||
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Inequality (a != b ) |
1 | 18 | 4 | 10.1 | 1 | 1.0 |
Server | |
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Inequality (a != b ) |
0.1.100 |
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https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Inequality