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This is especially true of cryptographic hash functions, which may be used to detect many data corruption errors and verify overall data integrity; if the computed checksum for the current data input matches the stored value of a previously computed checksum, there is a very high probability the data has not been accidentally altered or corrupted.
Presence check Checks that data is present, e.g., customers may be required to have an email address. Range check Checks that the data is within a specified range of values, e.g., a probability must be between 0 and 1. Referential integrity Values in two relational database tables can be linked through foreign key and primary key.
The length of a string can also be stored explicitly, for example by prefixing the string with the length as a byte value. This convention is used in many Pascal dialects; as a consequence, some people call such a string a Pascal string or P-string. Storing the string length as byte limits the maximum string length to 255.
Thus, an array of numbers with 5 rows and 4 columns, hence 20 elements, is said to have dimension 2 in computing contexts, but represents a matrix that is said to be 4×5-dimensional. Also, the computer science meaning of "rank" conflicts with the notion of tensor rank, which is a generalization of the linear algebra concept of rank of a matrix.)
the use of 2 to check whether a number is even or odd, as in isEven = (x % 2 == 0), where % is the modulo operator the use of simple arithmetic constants, e.g., in expressions such as circumference = 2 * Math.PI * radius , [ 1 ] or for calculating the discriminant of a quadratic equation as d = b^2 − 4*a*c
a = [3, 1, 5, 7] // assign an array to the variable a a [0.. 1] // return the first two elements of a a [.. 1] // return the first two elements of a: the zero can be omitted a [2..] // return the element 3 till last one a [[0, 3]] // return the first and the fourth element of a a [[0, 3]] = [100, 200] // replace the first and the fourth element ...
File verification is the process of using an algorithm for verifying the integrity of a computer file, usually by checksum. This can be done by comparing two files bit-by-bit, but requires two copies of the same file, and may miss systematic corruptions which might occur to both files.
A fixed-point data type uses the same, implied, denominator for all numbers. The denominator is usually a power of two.For example, in a hypothetical fixed-point system that uses the denominator 65,536 (2 16), the hexadecimal number 0x12345678 (0x1234.5678 with sixteen fractional bits to the right of the assumed radix point) means 0x12345678/65536 or 305419896/65536, 4660 + the fractional ...