Profile

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Turns the [[Profiler#CPU_profiling|JavaScript CPU profiler] on, which creates detailed statistics about function calls.

To stop profiling use profileEnd().

Contents

Syntax

profile([title])

Parameters

title

Summary for the profiler output.

This is displayed above the table including the statistics.

Examples

function getById(id)
{
    return document.getElementById(id);
}
 
function getViaSelector(id)
{
    return document.querySelector(id);
}
 
var numberOfCalls = 10000;
 
console.profile("getElementById() vs. querySelector()");
for (var i=0; i<numberOfCalls; ++i)
    getById("test");
for (var i=0; i<numberOfCalls; ++i)
    getViaSelector("test");
console.profileEnd();

This will compare the speed of the function document.getElementById() with the function document.querySelector(). The output of that code will look like this:

ProfilerOutputExample.png

See also

Personal tools