When an array is numerically [[Index (information technology)|indexed]], its range is the upper and lower bound of the array. Depending Inon mostthe [[programming languages]]environment, a warning, or possibly a [[fatal error]], (or [[bsod|worse]]!)unpredictable behavior will occur if youthe program tryattempts to access an array element that is outside the range. In some languages, such as [[C (programming language)|C]], arrays have a fixed lower bound (zero) and will contain data at each position up to the upper bound (so an array with 5 elements will have a range of 0 to 4). In others, such as [[PHP]], an array may have holes where no element is defined, and therefore an array with a range of 0 to 4 will have ''up to'' 5 elements (and a minimum of 2).
