Copy to new array and remove element?

Question

I need to copy one array and remove the element, but only from second array?

for example:

var  m1 = [ "a","b","c","d"];

var m2 = m1;

alert(m1+' and '+m2); // "a b c d" and "a b c d"

m2.splice(0,1); // b c d

alert(m1 + ' and ' + m2); // b c d and b c d

so the first element from each of these arrays was removed, but how to leave the 1st array static?

Answer 1

Use slice() to copy the values to the new array:

var m2 = m1.slice(0);

Answer 2

Use Array.prototype.slice to copy arrays:

var m2 = m1.slice();