How does <code>5.5 | 0 === 5</code> work? Is <code>| 0</code> in this context the bitwise <code>OR</code> I suspect it to be? If so, why does it cut off everything after the point?

Bitwise operators always coerce operands to 32-bit integers. The operation is interpreted as <pre class="prettyprint"><code>5.5 | (0 === 5) </code></pre> which is <pre class="prettyprint"><code>5.5 | false </code></pre> which is coerced to <pre class="prettyprint"><code>5.5 | 0 </code></pre> Now the <code>5.5</code> is converted to a 32-bit integer, so we have <pre class="prettyprint"><code>5 | 0 </code></pre> which is <code>5</code>. The relational operators bind more tightly than the bitwise operators which can be confusing. If you want to compare the result of a bitwise operator (unlike, say, an addition or multiplication), you have to parenthesize explicitly.

How does "5.5 | 0 === 5" work? [duplicate]

1 Answers

Bitwise operators always coerce operands to 32-bit integers.

The operation is interpreted as

5.5 | (0 === 5)

which is

5.5 | false

which is coerced to

5.5 | 0

Now the 5.5 is converted to a 32-bit integer, so we have

5 | 0

which is 5.

The relational operators bind more tightly than the bitwise operators which can be confusing. If you want to compare the result of a bitwise operator (unlike, say, an addition or multiplication), you have to parenthesize explicitly.