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Implementation of array_merge for JavaScript
/**
* @fileoverview array_merge and supporting functions.
* Designed to mimic PHP's array_merge function, however
* this function also takes into account that objects are
* used in place of associative arrays in JavaScript.
* @author Andrew Noyes noyesa@gmail.com
*/
(function () {
/**
* Returns the class name of object.
* @param object {Object}
* @returns Class name of object
* @type String
*/
var getClass = function (object) {
return Object.prototype.toString.call(object).slice(8, -1);
};
/**
* Returns true of obj is a collection.
* @param obj {Object}
* @returns True if object is a collection
* @type {bool}
*/
var isValidCollection = function (obj) {
try {
return (
typeof obj !== "undefined" && // Element exists
getClass(obj) !== "String" && // weed out strings for length check
typeof obj.length !== "undefined" && // Is an indexed element
!obj.tagName && // Element is not an HTML node
!obj.alert && // Is not window
typeof obj[0] !== "undefined" // Has at least one element
);
} catch (e) {
return false;
}
};
/**
* Merges an array with an array-like object or
* two objects.
* @param arr1 {Array|Object} Array that arr2 will be merged into
* @param arr2 {Array|NodeList|Object} Array-like object or Object to merge into arr1
* @returns Merged array
* @type {Array|Object}
*/
window.array_merge = function (arr1, arr2) {
// Variable declarations
var arr1Class, arr2Class, i, il;
// Save class names for arguments
arr1Class = getClass(arr1);
arr2Class = getClass(arr2);
if (arr1Class === "Array" && isValidCollection(arr2)) { // Array-like merge
if (arr2Class === "Array") {
arr1 = arr1.concat(arr2);
} else { // Collections like NodeList lack concat method
for (i = 0, il = arr2.length; i < il; i++) {
arr1.push(arr2[i]);
}
}
} else if (arr1Class === "Object" && arr1Class === arr2Class) { // Object merge
for (i in arr2) {
if (i in arr1) {
if (getClass(arr1[i]) === getClass(arr2[i])) { // If properties are same type
if (typeof arr1[i] === "object") { // And both are objects
arr1[i] = array_merge(arr1[i], arr2[i]); // Merge them
} else {
arr1[i] = arr2[i]; // Otherwise, replace current
}
}
} else {
arr1[i] = arr2[i]; // Add new property to arr1
}
}
}
return arr1;
};
})();
var a1 = {'aa':100, 'bb':2, 'cc':[6,7], 'dd':[12,13], 'ee':{'15':15,'16':16}};
var b1 = {'xx':101, 'bb':5, 'cc':8, 'dd':[14,15], 'ee':{'17':17,'18':18}};
var c = array_merge(a1, b1);
console.log(c);
// Output: {’aa’:100, ‘bb’: 5, ‘cc’:[6,7], ‘dd’:[12,13,14,15], ‘ee’:{’15′:15,’16′:16,’17′:17,’18′:18}, ‘xx’:101}
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