What is the difference between these code snippets?
1)
$f = 12.044545;
printf("%f",$f);
vprintf("%f",$f);
2)
echo("echo");
print("print");
Add a comment
|
5 Answers
printf()lets you specify the format of the variables you want to printvprintf()is the same asprintf()but accepts an array as argument instead of a list of scalar variablesechoandprintdo basically the same thing (besides technicalities): printing their argument(s) with no processing other than variable interpolation
Comments
1) printf and vprintf are almost the same, but vprintf accepts an array of arguments, instead of a variable number of arguments.
2) With echo, you can provide multiple expressions:
echo "Hello ", "Hello again";
print "Hello ", "Hello again"; // <- Error!
Comments
echo and print are not actually functions, and return no meaningful value. printf() and vprintf() return the length of the outputted string.
answered Jun 11, 2010 at 8:31
Ignacio Vazquez-Abrams
804k160 gold badges1.4k silver badges1.4k bronze badges
Comments
printf and vprintf are real functions that format text for output and return a value, whereas echo and print are just operators that output a string.
The printf family of functions are actually from a common family of output functions that go all the way back to the original K&R C and are well worth paying attention too because they occur in virtually all the C-syntax based languages. Get familiar with them in any one context and you'll be able to reach for them elsewhere with minimal trouble. One of the other useful variants on the theme is sprintf, which outputs a printf formatted expression to a string.
Of slightly less use, but also well worth having in the armoury as C heritage is the scanf function family which extracts data from formatted input. Like printf these occur in most C-syntax languages.
