Difference of Unary operators ( += , =+ , ++x , x++ )

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青春惊慌失措
青春惊慌失措 2021-01-14 04:56

What is the difference between these unary operators in C# ? . Can you provide me with example?

Please provide the name of each. :)

+= vs =+

++x vs

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  •  南方客
    南方客 (楼主)
    2021-01-14 05:22

    This has no doubt been answered before, but anyway...

    They differ in how they change the value and how they return the result.

    The first two += and =+ behave in the way that the first increments a variable, the other sets a variable. They are not related. Observe the following code:

    // +=
    x = 1;
    printf( x += 1 ); // outputs 2, the same as x = x+1
    printf( x );      // outputs 2
    
    // =+
    x = 1;
    printf( x =+ 1 ); // outputs 1, the same as x = 1;
    printf( x );      // outputs 1
    

    The next two, ++x and x++, differ in the order their function. ++x will increment your variable by 1 and return the result. x++ will return the result and increment by 1.

    // ++x
    x = 1;
    printf( ++x ); // outputs 2, the same as x = x+1
    printf( x );   // outputs 2
    
    // x++
    x = 1;
    printf( x++ ); // outputs 1
    printf( x );   // outputs 2
    

    They are mostly useful for for loops and while loops.

    In terms of speed, ++x is considered a lot faster than x++ since x++ needs to create an internal temporary variable to store the value, increment the main variable, but return the temporary variable, basically more operations are used. I learned this a looong time ago, I don't know if it still applies

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