Plus Equals New vs Equals Old Plus New

JavaScript performance comparison

Revision 3 of this test case created by Russell Dempsey

Info

I've always used

foo += bar;

for string concatenation but I'm curious how it performs against

foo = foo + bar;

at high volume.

Preparation code

 
<script>
Benchmark.prototype.setup = function() {
    var a = 'hello';
    var b = ' world, ';
};
</script>

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Testing in unknown unknown
Test Ops/sec
A Plus Equals B
a += b
pending…
A Equals A plus B
a = a + b
pending…

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