javascript - Coffeescript function is undefined -

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• how define global variables in coffeescript? 8 answers

i create coffeescript function square=(x)->alert x*x
it's compiled javascript

(function() {   var square;    square = function(x) {     return alert(x * x);   };  }).call(this); 

so if write code <button onclick="square(5)"> compiler says square() undefined. what's wrong?

your function square has globally defined function in order call html have defined. block of code:

(function() {   var square;    square = function(x) {     return alert(x * x);   };  }).call(this); 

does not define function globally, therefore symbol can't found. in fact, function square defined within iife , isn't available anywhere else. if want available globally, may change above block this:

window.square = function(x) {     return alert(x * x); } 

or, this:

(function() {     this.square = function(x) {        return alert(x * x);     }; }).call(this); 

or, apparently in coffeescript, @ sign shorthand this. can use this:

(function() {     @square = function(x) {        return alert(x * x);     }; }).call(this); 

or this:

@square = function(x) {    return alert(x * x); }; 

see other answer more info: how define global variables in coffeescript?

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even better not use calling method. if use event listeners instead, don't have make function global @ all.