Converts a string or number to a complex number

## Usage

The `complex()` function creates a complex number when real and imaginary parts are specified.

It can also convert a string to a complex number.

The complex number is returned in the form of real + imaginary, where the imaginary part is followed by a j.

## Syntax

complex(real,imaginary)

 Parameter Condition Description real Optional The real part of the complex number.Default is 0. imaginary Optional The imaginary part of the complex number.Default is 0.

## Creating Complex Numbers

You can create a complex number by specifying real and imaginary parts.

``````x = complex(3, 2)
print(x)
# Prints (3+2j)

x = complex(-3, 2)
print(x)
# Prints (-3+2j)

x = complex(3, -2)
print(x)
# Prints (3-2j)``````

If you omit one of the arguments, it is assumed as 0; because the default value of real and imaginary parameters is 0.

``````# omit imaginary part
x = complex(3)
print(x)
# Prints (3+0j)

# omit real part
x = complex(0, 4)
print(x)
# Prints 4j

# omit both
x = complex()
print(x)
# Prints 0j``````

## Convert a String to a Complex Number

You can convert a string to a complex number by specifying the first parameter as a string like `'3+4j'`. In this case the second parameter should be omitted.

``````# Convert a string '3+4j' to a complex number
x = complex('3+4j')
print(x)
# Prints (3+4j)``````

When converting from a string, the string must not contain whitespace around the central + or – operator. Otherwise, the function raises `ValueError`.

``````# Triggers ValueError: complex() arg is a malformed string
x = complex('3 + 4j')
print(x)``````