function isContain(arr1, arr2) {
var arr2Length = arr2.length;
if (arr2Length > arr1.length) return false; // quick check if arr2 is bigger than arr1 is always false
var lastPos = -1;
var i;
while (~(lastPos = arr1.indexOf(arr2[0], lastPos + 1))) {
for (i = 0; i < arr2Length; i++) {
if (arr1[lastPos + i] !== arr2[i]) break;
}
if (i === arr2Length ) return true;
}
return false;
}
console.log(isContain(["X","Y","Z","A","B","C","1","2","3"], ["A","B","C"]));
console.log(isContain(["X","Y","Z","A","D","B", "C","1","2","3"], ["A","B","C"]));
console.log(isContain(["X","Y","Z","A","B","C","1","2","3"], ["AB","C"]));
console.log(isContain(["X","Y","Z","AB","C","1","2","3"], ["AB","C"]));
console.log(isContain([false, false, true, false, false, true], [true, true]));
console.log(isContain([false, false, true, false, false, true], [true, false]));
console.log(isContain([false, false, true, false, false, true], [1, 0]));
console.log(isContain([1, 1], [1, 1, 1]));