CoffeeScript always returns in anonymous function

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余生分开走
余生分开走 2021-01-14 02:29

I\'m trying to write some CoffeScript function which checks all checkboxes in a table upon checking the checkbox in the th.

My function in CoffeeScript looks like th

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  •  花落未央
    2021-01-14 02:39

    Just add a true as the last line of your function, and coffeescript will compile the JS to return that instead:

    $("table.tableview th input:checkbox").live 'click', -> 
        checkedStatus = this.checked
        $("table.tableview tbody tr td:first-child input:checkbox").each ->
            this.checked = checkedStatus
        true
    

    In other words, CoffeeScript always returns the result of the last line (like Ruby does)


    Edit (after the question was updated):

    Again, you can't keep CoffeeScript from returning the value of the last line in a function - part of the point of CoffeeScript is that it does exactly that.

    CoffeeScript has significant whitespace, so indentation is what says what belongs together - your example is is actually correct:

    $("table.tableview th input:checkbox").live 'click', -> 
        checkedStatus = this.checked
        $("table.tableview tbody tr td:first-child input:checkbox").each ->
            this.checked = checkedStatus
            true // cause this function (the each-iterator) to return true
        true // causes the click handler function to return true
    

    There's no difference between this and just writing return true in a function like you would in javascript. You just use whitespace instead of {} to make code blocks.

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