[JAVASCRIPT] Array 관련 ( 셔플, contains, 초기화 )

* Shuffle

var intList = [ 10, 20, 30, 40, 50 ];

// shuffle
var array_shuffle = function(arr) {
   for(var j, x, i = arr.length; i; j = Math.floor(Math.random() * i), x = arr[--i], arr[i] = arr[j], arr[j] = x);
   return arr;
};

array_shuffle(intList);

for(var i in intList) {
    alert(intList[i]);
}

-> 10, 30, 20, 50, 40

 

 

* 초기화

var arrayList = new Array();

arrayList.push("a");

arrayList.push("b");

arrayList.push("c");

arrayList.splice(0, arrayList.length);

 

 

* contains

// contains
Array.prototype.contains = function(element) {
    for (var i = 0; i < this.length; i++) {
        if (this[i] == element) {
            return true;
        }
    }
    return false;
}

var arrayList = new ArrayList();

arrayList.push("apple");

arrayList.push("banana");

if ( arrayList.contains("apple") ) {

console.log("exist");

} else {

console.log("not exist");

}