Using PHP, what's the fastest way to convert a string like this: "123"
to an integer?
Why is that particular method the fastest? What happens if it gets unexpected input, such as "hello"
or an array?
This question is related to
php
optimization
casting
Run a test.
string coerce: 7.42296099663
string cast: 8.05654597282
string fail coerce: 7.14159703255
string fail cast: 7.87444186211
This was a test that ran each scenario 10,000,000 times. :-)
Co-ercion is 0 + "123"
Casting is (integer)"123"
I think Co-ercion is a tiny bit faster. Oh, and trying 0 + array('123')
is a fatal error in PHP. You might want your code to check the type of the supplied value.
My test code is below.
function test_string_coerce($s) {
return 0 + $s;
}
function test_string_cast($s) {
return (integer)$s;
}
$iter = 10000000;
print "-- running each text $iter times.\n";
// string co-erce
$string_coerce = new Timer;
$string_coerce->Start();
print "String Coerce test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_coerce('123');
}
$string_coerce->Stop();
// string cast
$string_cast = new Timer;
$string_cast->Start();
print "String Cast test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_cast('123');
}
$string_cast->Stop();
// string co-erce fail.
$string_coerce_fail = new Timer;
$string_coerce_fail->Start();
print "String Coerce fail test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_coerce('hello');
}
$string_coerce_fail->Stop();
// string cast fail
$string_cast_fail = new Timer;
$string_cast_fail->Start();
print "String Cast fail test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_cast('hello');
}
$string_cast_fail->Stop();
// -----------------
print "\n";
print "string coerce: ".$string_coerce->Elapsed()."\n";
print "string cast: ".$string_cast->Elapsed()."\n";
print "string fail coerce: ".$string_coerce_fail->Elapsed()."\n";
print "string fail cast: ".$string_cast_fail->Elapsed()."\n";
class Timer {
var $ticking = null;
var $started_at = false;
var $elapsed = 0;
function Timer() {
$this->ticking = null;
}
function Start() {
$this->ticking = true;
$this->started_at = microtime(TRUE);
}
function Stop() {
if( $this->ticking )
$this->elapsed = microtime(TRUE) - $this->started_at;
$this->ticking = false;
}
function Elapsed() {
switch( $this->ticking ) {
case true: return "Still Running";
case false: return $this->elapsed;
case null: return "Not Started";
}
}
}
More ad-hoc benchmark results:
$ time php -r 'for ($x = 0;$x < 999999999; $x++){$i = (integer) "-11";}'
real 2m10.397s
user 2m10.220s
sys 0m0.025s
$ time php -r 'for ($x = 0;$x < 999999999; $x++){$i += "-11";}'
real 2m1.724s
user 2m1.635s
sys 0m0.009s
$ time php -r 'for ($x = 0;$x < 999999999; $x++){$i = + "-11";}'
real 1m21.000s
user 1m20.964s
sys 0m0.007s
Run a test.
string coerce: 7.42296099663
string cast: 8.05654597282
string fail coerce: 7.14159703255
string fail cast: 7.87444186211
This was a test that ran each scenario 10,000,000 times. :-)
Co-ercion is 0 + "123"
Casting is (integer)"123"
I think Co-ercion is a tiny bit faster. Oh, and trying 0 + array('123')
is a fatal error in PHP. You might want your code to check the type of the supplied value.
My test code is below.
function test_string_coerce($s) {
return 0 + $s;
}
function test_string_cast($s) {
return (integer)$s;
}
$iter = 10000000;
print "-- running each text $iter times.\n";
// string co-erce
$string_coerce = new Timer;
$string_coerce->Start();
print "String Coerce test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_coerce('123');
}
$string_coerce->Stop();
// string cast
$string_cast = new Timer;
$string_cast->Start();
print "String Cast test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_cast('123');
}
$string_cast->Stop();
// string co-erce fail.
$string_coerce_fail = new Timer;
$string_coerce_fail->Start();
print "String Coerce fail test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_coerce('hello');
}
$string_coerce_fail->Stop();
// string cast fail
$string_cast_fail = new Timer;
$string_cast_fail->Start();
print "String Cast fail test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_cast('hello');
}
$string_cast_fail->Stop();
// -----------------
print "\n";
print "string coerce: ".$string_coerce->Elapsed()."\n";
print "string cast: ".$string_cast->Elapsed()."\n";
print "string fail coerce: ".$string_coerce_fail->Elapsed()."\n";
print "string fail cast: ".$string_cast_fail->Elapsed()."\n";
class Timer {
var $ticking = null;
var $started_at = false;
var $elapsed = 0;
function Timer() {
$this->ticking = null;
}
function Start() {
$this->ticking = true;
$this->started_at = microtime(TRUE);
}
function Stop() {
if( $this->ticking )
$this->elapsed = microtime(TRUE) - $this->started_at;
$this->ticking = false;
}
function Elapsed() {
switch( $this->ticking ) {
case true: return "Still Running";
case false: return $this->elapsed;
case null: return "Not Started";
}
}
}
integer excract from any string
$in = 'tel.123-12-33';
preg_match_all('!\d+!', $in, $matches);
$out = (int)implode('', $matches[0]);
//$out ='1231233';
I personally feel casting is the prettiest.
$iSomeVar = (int) $sSomeOtherVar;
Should a string like 'Hello' be sent, it will be cast to integer 0. For a string such as '22 years old', it will be cast to integer 22. Anything it can't parse to a number becomes 0.
If you really do NEED the speed, I guess the other suggestions here are correct in assuming that coercion is the fastest.
You can simply convert long string into integer by using FLOAT
$float = (float)$num;
Or if you want integer not floating val then go with
$float = (int)$num;
For ex.
(int) "1212.3" = 1212
(float) "1212.3" = 1212.3
More ad-hoc benchmark results:
$ time php -r 'for ($x = 0;$x < 999999999; $x++){$i = (integer) "-11";}'
real 2m10.397s
user 2m10.220s
sys 0m0.025s
$ time php -r 'for ($x = 0;$x < 999999999; $x++){$i += "-11";}'
real 2m1.724s
user 2m1.635s
sys 0m0.009s
$ time php -r 'for ($x = 0;$x < 999999999; $x++){$i = + "-11";}'
real 1m21.000s
user 1m20.964s
sys 0m0.007s
I personally feel casting is the prettiest.
$iSomeVar = (int) $sSomeOtherVar;
Should a string like 'Hello' be sent, it will be cast to integer 0. For a string such as '22 years old', it will be cast to integer 22. Anything it can't parse to a number becomes 0.
If you really do NEED the speed, I guess the other suggestions here are correct in assuming that coercion is the fastest.
Ran a benchmark, and it turns out the fastest way of getting a real integer (using all the available methods) is
$foo = (int)+"12.345";
Just using
$foo = +"12.345";
returns a float.
$int = settype("100", "integer"); //convert the numeric string to int
You can simply convert long string into integer by using FLOAT
$float = (float)$num;
Or if you want integer not floating val then go with
$float = (int)$num;
For ex.
(int) "1212.3" = 1212
(float) "1212.3" = 1212.3
integer excract from any string
$in = 'tel.123-12-33';
preg_match_all('!\d+!', $in, $matches);
$out = (int)implode('', $matches[0]);
//$out ='1231233';
I personally feel casting is the prettiest.
$iSomeVar = (int) $sSomeOtherVar;
Should a string like 'Hello' be sent, it will be cast to integer 0. For a string such as '22 years old', it will be cast to integer 22. Anything it can't parse to a number becomes 0.
If you really do NEED the speed, I guess the other suggestions here are correct in assuming that coercion is the fastest.
Ran a benchmark, and it turns out the fastest way of getting a real integer (using all the available methods) is
$foo = (int)+"12.345";
Just using
$foo = +"12.345";
returns a float.
Run a test.
string coerce: 7.42296099663
string cast: 8.05654597282
string fail coerce: 7.14159703255
string fail cast: 7.87444186211
This was a test that ran each scenario 10,000,000 times. :-)
Co-ercion is 0 + "123"
Casting is (integer)"123"
I think Co-ercion is a tiny bit faster. Oh, and trying 0 + array('123')
is a fatal error in PHP. You might want your code to check the type of the supplied value.
My test code is below.
function test_string_coerce($s) {
return 0 + $s;
}
function test_string_cast($s) {
return (integer)$s;
}
$iter = 10000000;
print "-- running each text $iter times.\n";
// string co-erce
$string_coerce = new Timer;
$string_coerce->Start();
print "String Coerce test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_coerce('123');
}
$string_coerce->Stop();
// string cast
$string_cast = new Timer;
$string_cast->Start();
print "String Cast test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_cast('123');
}
$string_cast->Stop();
// string co-erce fail.
$string_coerce_fail = new Timer;
$string_coerce_fail->Start();
print "String Coerce fail test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_coerce('hello');
}
$string_coerce_fail->Stop();
// string cast fail
$string_cast_fail = new Timer;
$string_cast_fail->Start();
print "String Cast fail test\n";
for( $i = 0; $i < $iter ; $i++ ) {
test_string_cast('hello');
}
$string_cast_fail->Stop();
// -----------------
print "\n";
print "string coerce: ".$string_coerce->Elapsed()."\n";
print "string cast: ".$string_cast->Elapsed()."\n";
print "string fail coerce: ".$string_coerce_fail->Elapsed()."\n";
print "string fail cast: ".$string_cast_fail->Elapsed()."\n";
class Timer {
var $ticking = null;
var $started_at = false;
var $elapsed = 0;
function Timer() {
$this->ticking = null;
}
function Start() {
$this->ticking = true;
$this->started_at = microtime(TRUE);
}
function Stop() {
if( $this->ticking )
$this->elapsed = microtime(TRUE) - $this->started_at;
$this->ticking = false;
}
function Elapsed() {
switch( $this->ticking ) {
case true: return "Still Running";
case false: return $this->elapsed;
case null: return "Not Started";
}
}
}
I personally feel casting is the prettiest.
$iSomeVar = (int) $sSomeOtherVar;
Should a string like 'Hello' be sent, it will be cast to integer 0. For a string such as '22 years old', it will be cast to integer 22. Anything it can't parse to a number becomes 0.
If you really do NEED the speed, I guess the other suggestions here are correct in assuming that coercion is the fastest.
$int = settype("100", "integer"); //convert the numeric string to int
Source: Stackoverflow.com