require checks if the file was already executed. do EXPR doesn't.

The makes require the better choice when loading a module (a file with a package directive), and do otherwise (i.e. never).

do also has an unrelated do BLOCK form which is useful for inlining multiple statements into an expression.

In reply to Re: require() vs do() by ikegami
in thread require() vs do() by vinoth.ree

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