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JavaScript JavaScript Functions Create Reusable Code with Functions Using Multiple return Statements

David Douglas
David Douglas
3,719 Points
Posted by David Douglas
David Douglas
3,719 Points

Calling function vs stored in variable

What is the benefit of storing a function in a variable if it performs the same function as it would if you called the function.

function isFieldEmpty(){ const field = document.querySelector('#info'); if(!field.value){ return true; } else{ return false } }

const fieldTest = isFieldEmpty()

if(fieldTest()){ alert('Please enter info into field'); }

VS

function isFieldEmpty(){ const field = document.querySelector('#info'); if(!field.value){ return true; } else{ return false } }

if(isFieldEmpty()){ alert('Please enter info into field'); }

1 Answer

Steven Parker
Steven Parker
231,236 Points
Steven Parker
Steven Parker
231,236 Points

As shown here, the only advantage is that "fieldTest" is immutable where "isFieldEmpty" could be redefined. In such a simple case it doesn't make any practical difference, so this mechanism would be better used in other situations.

Another difference (which also has no bearing on this case) would be hoisting (which allows the function to be called before it is defined, but not the variable).