What is atoi in string?

The atoi() function converts a character string to an integer value. The input string is a sequence of characters that can be interpreted as a numeric value of the specified return type. The function stops reading the input string at the first character that it cannot recognize as part of a number.

After-tax operating income (ATOI) is a company's total operating income after taxes. This non-GAAP measure excludes any after-tax benefits or charges such as effects from accounting changes.

Where operating income is (gross revenue - operating expenses - depreciation), also known as the pre-tax operating income (PTOI).

The operating income is a measure of how much of a company's revenue will eventually become profit. After-tax operating income (ATOI) measures a company's ability to generate income from its operations for a specified time period. It is simply the operating income (or loss) generated by a company after factoring in the effect of taxes. In effect, it is earnings before interest and taxes (EBIT), adjusted for taxes. Thus, it can also be calculated as:

Some analysts choose to use the effective tax rate of the firm, others opt for the marginal tax rate. Furthermore, some calculate after-tax operating income as:

The after-tax operating income can also be defined as earnings before interest and after taxes (EBIAT). It measures a company's profitability without taking into account the capital structure (debt to equity). ATOI is an approximation of after-tax cash flows without the tax advantage of debt. A company that does not have debt, will have its ATOI equal its net income after tax (NIAT).

Due to its non-GAAP nature, what is included and excluded in the measure differs across companies and industries, therefore, it is important to understand how the company under analysis arrived at its ATOI value.

Atoi in C++ is a predefined function from the cstdlib header file used to convert a string value to an integer value. There are many scenarios where you might need to convert a string with an integer value to an actual integer value, and that’s where the C++ atoi() function comes in.

The str argument is a string, represented by an array of characters, containing the characters of a signed integer number. The string must be null-terminated. When atoi encounters a string with no numerical sequence, it returns zero (0).

There are several variants of the atoi function, atol, atof and atoll , which are used to convert a string into a long, double, or long long type, respectively. The atoll was formerly known as atoq and was included into C99.

It is impossible to tell whether the string holds valid sequence of digits that represents the number 0 or invalid number as the function returns 0 in both cases. The newer function strtol does not have this deficiency.

atoi is neither thread-safe, nor async-cancel safe on some operating systems.[1]

Also, atoi only converts base ten ascii values (this may also be a benefit depending on perspective). strtol and other functions support alternate bases such as hexadecimal and octal.

The atoi, atof, and atol functions are a part of the ISO standard C library (C89), while the atoll function is added by C99.

However, because of the ambiguity in returning 0 and lack of thread-safety and async-cancel safety on some operating systems, atoi is considered to be deprecated by strtol.[1]

The Version 7 Unix Manual Pages © 1979 by Bell Telephone Laboratories, Incorporated.

The Version 1 Unix Manual page for atoi written by Ken Thompson (November 1971).