# NumPy Matrix of All True or All False

In this tutorial, we will learn how to create a NumPy matrix of all True or all False? By Pranit Sharma Last updated : May 25, 2023

Suppose we need to create a numpy matrix of length n x n, and each element of this array would be either True or False.

## How to create a NumPy Matrix of All True or All False?

There are three different approaches that you can use to create a NumPy matrix of all True or all False,

1. Using numpy.full() Method
2. Using numpy.ones() Method
3. Using numpy.zeroes() Method

## 1) Using numpy.full() Method

In this approach, simply use numpy.full() and pass the number of rows and columns and True. It will create a matrix of all True.

### Example 1: NumPy Matrix of All True or All False Using numpy.full() Method

```# Import numpy
import numpy as np

# Numpy Matrix of all True
arr1 = np.full((2, 2), True)

# Numpy Matrix of all False
arr2 = np.full((2, 2), False)

# Printing
print("arr1:\n",arr1,"\n")
print("arr2:\n",arr2,"\n")
```

```arr1:
[[ True  True]
[ True  True]]

arr2:
[[False False]
[False False]]
```

## 2) Using numpy.ones() Method

In this approach, simply use numpy.ones() method, it returns a new array of given shape and data type, where the element's value is set to 1.

### Example 2: NumPy Matrix of All True Using numpy.ones() Method

```# Import numpy
import numpy as np

# Creating numpy array
arr = np.ones((2, 2), dtype=bool)

# Printing
print("arr:\n",arr,"\n")
```

```arr:
[[ True  True]
[ True  True]]
```

## 3) Using numpy.zeroes() Method

In this approach, simply use numpy.zeroes() method, it returns a new array of given shape and data type, where the element's value is set to 0.

### Example 3: NumPy Matrix of All False Using numpy.zeroes() Method

```# Import numpy
import numpy as np

# Creating numpy array
arr = np.zeros((2, 2), dtype=bool)

# Printing
print("arr:\n",arr,"\n")
```

```arr:
[[False False]
[False False]]
```