+,! in front of JavaScript functions Usage introduction

+function(){}();

The plus sign here can also be replaced with !,~ and other unary operators, the effect is equivalent to:

(function() { console.log("Foo!"); })();  
// or  (function() { console.log("Foo!"); }());

Without this plus sign, the parser will think that function is the beginning of a function declaration, and the following () will cause a syntax error. When a + sign is added in front of function, it becomes a function expression, and when a () is added after the function expression, it becomes an immediately executed function.

The above is the detailed content of +,! in front of JavaScript functions Usage introduction. For more information, please follow other related articles on the PHP Chinese website!