coder_life
Built-in objects-Array
Array Sparse array Sparse array with null values in itemptySparse array // 1 When we delete the items of the array, there will be empty in the array var arr = [ 1 , 2 , 3 , 4 , 5 ] delete arr[ 1 ] console .log(arr) => [ 1 , empty, 3 , 4 , 5 ] // array we see what we call a null value appears array scrim // 2 when we play more comma 'in the array, there will be' empty var ARR = [ . 1 ,, . 3 , 4 , 5 ] console .log(arr) => [ 1 , empty, 3 , 4 , 5] // We see empty values in the array // Of cour