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Parameters and Arguments

JavaScript: The Complete '0 to Hero' Beginner Course

43. Parameters and Arguments

It's important to distinguish between parameters and arguments when working with functions.

Parameters

Parameters are the variable names listed in the function definition. They act as placeholders for the values the function expects to receive.

javascript // 'p1' and 'p2' are parameters function subtract(p1, p2) { console.log(p1 - p2); }

Arguments

Arguments are the actual values passed to the function when it is called.

javascript subtract(10, 3); // 10 and 3 are the arguments // Output: 7

Handling Missing Arguments

If you call a function without providing enough arguments, the missing parameters are automatically assigned the value undefined.

javascript function log(message, level) { console.log([${level}]: ${message}); }

log('System startup'); // level will be undefined // Output: [undefined]: System startup