atoi

The atoi (ASCII to Integer[1]) function in the C programming language is used to convert a string into a numerical representation.int atoi (const char *string) Where string is the string, represented by an array of characters. When atoi encounters a string with no numerical sequence, it returns a 0 (zero). Also, if the string holds a valid sequence of digits that represents the number 0, it would also return a 0, making it impossible to tell from the return value alone whether the string held a valid number or not. The newer function strtol does not have this deficiency.
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