Undefined variable information

An undefined variable in the source code of a computer program is a variable that is accessed in the code but has not been declared by that code. In some...

correct value Undefined variable Undefined, a function or variable lacking a declaration Undefined, a variable lacking initialization Undefined, an unavailable...

In computer programming, undefined behavior (UB) is the result of executing a program whose behavior is prescribed to be unpredictable, in the language...

usually treat undefined values explicitly when possible. For instance, Perl has undef operator which can "assign" such value to a variable. In other type...

Lovelace defines a hitherto undefined variable ( V 13 {\displaystyle V_{13}} ) by itself, thereby assuming that all undefined variables are automatically equal...

the special \nnn octal notation supported, see %$CLS%. While the variable is undefined by default under DOS Plus and DR-DOS, the Multiuser DOS default...

first line were omitted, the program would trigger an error on the undefined variable p during compilation. However, the program would still be syntactically...

required every time an undefined value is dereferenced. Perl autovivification allows a programmer to refer to a structured variable, and arbitrary sub-elements...

is undefined. The answer that it must be 10 assumes that it started at zero, which may or may not be true. Note that in the example, the variable i is...

values at the last exit, while the values of declared variables that are not marked with own is undefined. — Revised report on ALGOL 60, section "5. Declarations"...

results are not trustworthy. Using aqueous electrodes introduces undefined, variable, and unmeasurable junction potentials to the cell in the form of...

random variables, one can show that both E[X +] = ∞ and E[X −] = ∞ (see Harmonic series). Hence, in this case the expectation of X is undefined. Similarly...

"pathological" distribution since both its expected value and its variance are undefined (but see § Moments below). The Cauchy distribution does not have finite...

is reported to the user as an undefined variable. This has the pleasant side effect of checking for undefined variables with essentially no CPU overhead...

automatic variables.) All variables declared within a block of code are automatic by default. An uninitialized automatic variable has an undefined value until...

forward reference is not possible. With var a variable's value is undefined until it is initialized. Variables declared with let or const cannot be accessed...

Cauchy distribution. The distributions have undefined variance for α < 2 {\displaystyle \alpha <2} , and undefined mean for α ≤ 1 {\displaystyle \alpha \leq...

programming, values held in program variables whose content never changes are known as constants to differentiate them from variables that could be altered during...

is undefined. GCC extends the C language with a unary && operator that returns the address of a label. This address can be stored in a void* variable type...

00, is a mathematical expression that is either defined as 1 or left undefined, depending on context. In algebra and combinatorics, one typically defines...

would be undefined (because the multiplications 0 ⋅ ∞ {\displaystyle 0\cdot \infty } and 0 ⋅ ( − ∞ ) {\displaystyle 0\cdot (-\infty )} are undefined). The...

Bihar. Falling Rain Genomics. Retrieved 10 March 2009. " Notice: Undefined variable: Post in /Opt/Lampp/Htdocs/Zhouyong/Icas.co.in/List.PHP on line 29...

expectation of a circularly symmetric complex random variable can only be either zero or undefined. Additionally, E ⁡ [ Z Z ] = E ⁡ [ e i ϕ Z e i ϕ Z ]...

variable, coded by an indicator variable, where the two values are labeled "0" and "1", while the independent variables can each be a binary variable...

and HTML elements in the Document Object Model (DOM). When an undefined JavaScript variable is declared in the same context as an HTML element with the...