In this way, let works very much like var. Notes Prior to Firefox 46, a TypeError is thrown on redeclaration instead of a SyntaxError. } You may encounter errors in statements because there is only one block. Notes Firefox 54 adds support of let in workers. Description let allows you to declare variables that are limited in scope to the block, statement, or expression on which it is used.
Does not specify let expressions or let blocks. User must explicitly enable this feature. User must explicitly enable this feature. This is unlike the keyword, which defines a variable globally, or locally to an entire function regardless of block scope. Unlike variables declared with , which will start with the value undefined, let variables are not initialized until their definition is evaluated. Redeclarations Redeclaring the same variable within the same function or block scope raises a. Note the difference between var whose scope is inside the function where it is declared.
. The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone and send us a pull request. Notes Firefox 54 adds support of let in workers. . .
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