In es5, you can use indexOf to get the index of one item in an array.
In es6, you can use findIndex(), which is more prowful:
[NaN].indexOf(NaN) // -1 [NaN].findIndex(y => Object.is(NaN, y)) //0
You can use with splice() function:
_cartItems.splice( _cartItems.findIndex( i => i === item ), 1 );
原文：http://www.cnblogs.com/Answer1215/p/4957851.html