# NullOrEmpty-Checks

{% hint style="info" %}
Included since 📦**v1.1.0**
{% endhint %}

### **Regular version**

#### **Summary**

The extension methods `IsNullOrEmpty()` and `IsNullOrWhiteSpace()` return a boolean value that indicates whether the value of the string instance is null / empty / only consisting of whitespace characters.

They mirror the behaviour of the string class's pre-existing methods of the same name.

#### **Example**

```csharp
// Suppose we have a string variable.
var myString = "foo";

// This library lets you check whether it is null or empty (or whitespace)
// using an extension method.
myString.IsNullOrEmpty();
myString.IsNullOrWhiteSpace();

// In each case a boolean value is returned indicating the answer
// (here: 'false').
```

#### **Equivalent to**

```csharp
// Conventionally, one would check whether the string is null or empty
// (or whitespace) like this:
string.IsNullOrEmpty(myString);
string.IsNullOrWhiteSpace(myString);
```

### Negated version

#### **Summary**

The extension methods `IsNotNullOrEmpty()` and `IsNotNullOrWhiteSpace()` return a boolean value that indicates whether the value of the string instance is *not* null / empty / only consisting of whitespace characters.

They mirror the behaviour of the string class's pre-existing methods of similar name (but return the negated result).

#### **Example**

```csharp
// Suppose we have a string variable.
var myString = "foo";

// This library lets you check whether it is *not* null or empty
// (or whitespace) using an extension method.
myString.IsNotNullOrEmpty();
myString.IsNotNullOrWhiteSpace();

// In each case a boolean value is returned indicating the answer
// (here: 'true').
```

#### **Equivalent to**

```csharp
// Conventionally, one would check whether the string is not null or empty
// (or whitespace) like this:
!string.IsNullOrEmpty(myString);
!string.IsNullOrWhiteSpace(myString);
```


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