Predefined Constants
The constants below are always available as part of the PHP core.
- Mathematical Constants
M_PI(float)- Approximation of the number π (pi). (
3.14159265358979323846). M_E(float)- Approximation of Euler's number
e(2.7182818284590452354). M_LOG2E(float)- Approximation of
log2(e)(1.4426950408889634074). M_LOG10E(float)- Approximation of
log10(e)(0.43429448190325182765). M_LN2(float)- Approximation of
ln(2)(0.69314718055994530942). M_LN10(float)- Approximation of
ln(10)(2.30258509299404568402). M_PI_2(float)- Approximation of
π/2(1.57079632679489661923). M_PI_4(float)- Approximation of
π/4(0.78539816339744830962). M_1_PI(float)- Approximation of
1/π(0.31830988618379067154). M_2_PI(float)- Approximation of
2/π(0.63661977236758134308). M_SQRTPI(float)- Approximation of
sqrt(π)(1.77245385090551602729). M_2_SQRTPI(float)- Approximation of
2/sqrt(π)(1.12837916709551257390). M_SQRT2(float)- Approximation of
sqrt(2)(1.41421356237309504880). M_SQRT3(float)- Approximation of
sqrt(3)(1.73205080756887729352). M_SQRT1_2(float)- Approximation of
1/sqrt(2)(0.70710678118654752440). M_LNPI(float)- Approximation of
ln(π)(1.14472988584940017414). M_EULER(float)- Approximation of Euler's constant γ (
0.57721566490153286061).
- Rounding constants
PHP_ROUND_HALF_UP(int)- Rounding half away from zero.
PHP_ROUND_HALF_DOWN(int)- Rounding half toward zero.
PHP_ROUND_HALF_EVEN(int)- Round halves to even numbers
PHP_ROUND_HALF_ODD(int)- Round halves to odd numbers
Note: As of PHP 8.4.0, it is recommended to use the RoundingMode enum instead.
↑ and ↓ to navigate • Enter to select • Esc to close • / to open