Question

How to set a default value to function parameters in Rust

Answer 1

// In Rust, you can't set default values for function parameters.
// However, you can achieve a similar effect using optional parameters with the Option type.

fn my_function(param: Option<i32>) {
    let param = param.unwrap_or(-1);
    
    println!("param: {}", param);
}

fn main() {
    my_function(Some(100)); 
    
    my_function(None);     
}

 
 
 
   
/*
run:
   
param: 100
param: -1
  
*/

 

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Answer 2

// In Rust, you can't set default values for function parameters.

// Another approach is to use function overloading by defining multiple versions 
// of the function, each with a different number of parameters

fn my_function(param: i32) {
    println!("param: {}", param);
}

fn my_function_with_default() {
    my_function(-1);
}

fn main() {
    my_function(100);         
    my_function_with_default(); 
}

 
 
   
/*
run:
   
param: 100
param: -1
  
*/

 

70+ SQL courses for beginners and professionals