帶反向循環參數的函數

Question

在JavaScript中有什麼方法可以將參數傳遞給函數，以便反轉循環的方向？

var srcDoc = app.activeDocument; 
var str = ""; 

// iterateLayers(srcDoc, true); // 3 2 1 0 
iterateLayers(srcDoc, false); // 0 1 2 3 

function iterateLayers(srcDoc, rev) 
{ 
    var numOfLayers = sauce.layers.length; 
    if (rev) 
    { 
    for (var i = numOfLayers -1; i >= 0; i--) 
    { 
     str+= i + " "; 
    } 
    } 
    else 
    { 
    for (var i = 0; i < numOfLayers; i++) 
    { 
     str+= i + " "; 
    } 
    } 
} 

alert(str); 

Answer 1

哈！我用三元運算符來解決這個問題。走吧！

// call the source document 
var srcDoc = app.activeDocument; 

var str = ""; 

// iterateLayers(srcDoc, true); // 3 2 1 0 
iterateLayers(srcDoc, false); // 0 1 2 3 

function iterateLayers(sauce, rev) 
{ 
    var numOfLayers = sauce.layers.length; 
    for (var i = numOfLayers -1; i >= 0; i--) 
    { 
    var index = (rev == true) ? i : (sauce.layers.length-i)-1; 
    str+= index + " "; 
    } 
} 

alert(str);