bin2dec

Convert text representation of binary integer to double value

Syntax

D = bin2dec(binStr)

Description

D = bin2dec(binStr) converts the binary integer represented by binStr to the equivalent decimal number and returns it as a double-precision floating-point value.

If binStr represents an integer greater than or equal to flintmax, then bin2dec might not represent it exactly as a floating-point value.

Examples

Convert Text Representing Binary Value

Convert a character vector that represents a binary value to a decimal number.

binStr = '10111';
D = bin2dec(binStr)

D = 
23

Starting in R2019b, you can write values in binary format directly without using bin2dec. Use the 0b prefix and do not use quotation marks. MATLAB® stores the value as an integer, not as text.

D = 0b10111

D = uint8

23

Return Numeric Array

Create a string array that represents multiple binary values.

binStr = ["1111111111" "1111010" "1110"]

binStr = 1x3 string
    "1111111111"    "1111010"    "1110"

Convert the binary values and return a numeric array.

D = bin2dec(binStr)

D = 1×3

        1023         122          14

Starting in R2019b, it is recommended that you create a numeric array using binary literals instead of converting text with bin2dec.

D = [0b1111111111 0b1111010 0b1110]

D = 1x3 uint16 row vector

   1023    122     14

Input Arguments

binStr — Text representing binary numbers

character array | cell array of character vectors | string array

Text representing binary numbers, specified as a character array, cell array of character vectors, or string array. binStr represents binary digits using the characters 0 and 1.

• If binStr is a character array with multiple rows or a cell array of character vectors, then the output is a numeric column vector.

• If binStr is a string array, then the output is a numeric array that has the same dimensions.

A binary number represented by binStr can have no more than 53 digits.

Starting in R2020a, binStr can be text that includes the same prefixes (0b or 0B) and suffixes used by binary literals. For example, these calls to bin2dec each return the number 7.

bin2dec('111')
bin2dec('0b111')
bin2dec('0b111s32')

Also, in R2020a binStr can represent the two's complement of a negative number, using a suffix that specifies a signed integer type. For example, bin2dec('0b11111111s8') returns -1, because the s8 suffix specifies the 8-bit signed integer type. In previous releases, binStr cannot represent a negative number.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• Input text must be specified as a character array or a string scalar. Cell arrays are not supported.

• When the input is empty, the answer does not match the answer in MATLAB^®.

GPU Code Generation

Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Usage notes and limitations:

• Input text must be specified as a character array. Cell arrays are not supported.

• When the input is empty, the answer does not match the answer in MATLAB.

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

Version History

Introduced before R2006a

R2020b: Issue warning when input values are greater than or equal to flintmax

The bin2dec function issues a warning when input values are greater than or equal to flintmax. In previous releases, bin2dec did not issue this warning.

bin2dec now issues a warning because inputs representing integers greater than or equal to flintmax might not be represented exactly as double-precision floating-point values.

To convert values greater than flintmax exactly, consider one of these alternatives:

• In place of scalar text inputs, use hexadecimal or binary literals representing the same values. When you write a value as a literal, MATLAB stores it as an integer that represents the value exactly. For more information, see Hexadecimal and Binary Values.

• To convert hexadecimal inputs greater than flintmax, you can use the sscanf function with the %lx operator. When you use %lx, the converted values are integers that have the uint64 data type. These integers have enough storage to represent values greater than flintmax exactly.

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