# How to change data type of a given NumPy array?

`astype()` function is used to change the data type of a given array. This function takes data type as an argument in which you want to change array.

## Syntax of numpy.ndarray.astype()

`numpy.ndarray.astype(dtype)`

`dtype` parameter is used to specify the data type in which you want to change the given Numpy array.

Example 1: Here, we will change the data type of array from int64 to float64.

```import numpy as np

x = np.array([12, 24, 36, 48])
print('Array a:', x)
print('Data type of array a:', x.dtype)
x = x.astype('float64')
print('Data type of array a after calling astype():', x.dtype)
print('Array a:', x)```

Output of the above program

```Array a: [12 24 36 48]
Data type of array a: int64
Data type of array a after calling astype(): float64
Array a: [12. 24. 36. 48.]```

Example 2: In this example, we will change the data type of array from float64 to complex128

```import numpy as np

x = np.array([1.2, 2.04, 36.65, 48])
print('Array a:', x)
print('Data type of array a:', x.dtype)
x = x.astype('complex128')
print('Data type of array a after calling astype():', x.dtype)
print('Array a:', x)```

Output of the above program

```Array a: [ 1.2   2.04 36.65 48.  ]
Data type of array a: float64
Data type of array a after calling astype(): complex128
Array a: [ 1.2 +0.j  2.04+0.j 36.65+0.j 48.  +0.j]```