Arduino - character judgment function

Arduino - Character judging function

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Character judging function , Although it may be rarely used in actual programming , But it can be used as a knowledge reserve , It's necessary to know something about . These functions are contained in ctype.h among .

• Arduino IDE route ：C:\Program Files (x86)\Arduino\hardware\tools\avr\avr\include

int isdigit( int c )： If c It's the number. , Then return to 1, Otherwise return to 0.

int isalpha( int c )： If c It's the letters , Then return to 1, Otherwise return to 0.

int isalnum( int c )： If c It's numbers or letters , Then return to 1, Otherwise return to 0.

int isxdigit( int c )： If c It's a hexadecimal numeric character , Then return to 1, Otherwise return to 0.

int islower( int c )： If c It's lowercase , Then return to 1, Otherwise return to 0.