If-Else Chain VS Switch(true)
JavaScript performance comparison
Revision 8 of this test case created
Info
This test is to attempt to determine if there is any notable performance difference when using switch(true) instead of a chain of if-else statements.
Preparation code
<script>
var strs = ['apple','banana','pear','lemon','grape','orange'], len = strs.length;
</script>
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Testing in unknown unknown
| Test |
Ops/sec |
If-Else Chain |
for(var i = len; i--;) {
var str = strs[i];
if(/p{2}le/.test(str))
var some_var = 'found apple';
else if(/(an){2}a/.test(str))
var some_var = 'found banana';
else if(/^[a-z][a-z][a-z][a-z]$/.test(str))
var some_var = 'found pear';
else if(str.indexOf("lemon") != -1)
var some_var = 'found lemon';
else if(/ape/.test(str))
var some_var = 'found grape';
else
var some_var = 'found else (orange)';
}
|
pending… |
switch(true) |
for(var i = len; i--;) {
var str = strs[i];
switch(true) {
case /p{2}le/.test(str):
return 'found apple';
case /(an){2}a/.test(str):
return 'found banana';
case /^[a-z][a-z][a-z][a-z]$/.test(str):
return 'found pear';
case (str.indexOf("lemon") != -1):
return 'found lemon';
case /ape/.test(str):
return 'found grape';
default:
return 'found else (orange)';
}
}
|
pending… |
ternary |
for(var i = len; i--;) {
var str = strs[i];
var some_var = /p{2}le/.test(str) ? 'found apple' :
/(an){2}a/.test(str) ? 'found banana' :
/^[a-z][a-z][a-z][a-z]$/.test(str) ? 'found pear' :
(str.indexOf("lemon") != -1) ? 'found lemon' :
/ape/.test(str) ? 'found grape' : 'found else (orange)';
}
|
pending… |
short-circuit |
for(var i = len; i--;) {
var str = strs[i];
var some_var = /p{2}le/.test(str) && 'found apple' ||
/(an){2}a/.test(str) && 'found banana' ||
/^[a-z][a-z][a-z][a-z]$/.test(str) && 'found pear' ||
(str.indexOf("lemon") != -1) && 'found lemon' ||
/ape/.test(str) && 'found grape' || 'found else (orange)';
}
|
pending… |
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