Check if one tab contain the other

gistfile1.js

// Test tab
var tab1 = [1, 2, 3, 4, 5 ];
var tab2 = [1, 2, 3, 4 ];
// Hash to compare
var compare = {};
var found = true;

// Clone the tab
for ( var i in tab1 ) {
    compare[tab1[i]] = tab1[i];   
}

// use "in" operator to know if all element of tab2 are in tab1
for ( var i in tab2 ) {
    if ( ! ( tab2[i] in compare ) ) {
      found = false;
      break;
    }
}

// found == true  tab1 contain all tab2 elements