JavaScript function parameter restrictions description_javascript skills

Test results:

There are 65535 under safari. That is ushort to store (2 bytes 16 1). More are ignored.

Other browsers are at least int.MaxValue. It is said that FireFox even uses long to maintain real parameters.

Other browsers may be int or maybe uint. Don’t worry about it. After all, we know the bottleneck is at 65535.

Based on the above foundation. You can consider using [].push.apply(a,b) instead of a=a.concat(b) when connecting arrays;

We just need to note that for safari, the length of b cannot exceed 65535.

The problem with

concat is that the new array generated traverses the two arrays a and b, and then puts the elements of a and b in sequence.

Test code:

var count = 100000, a = [1,2,3], b = [4,5,6], r = [], i, d;

d = new Date ;
for (i = count; i-- ;){
a.concat(b);
}
r[0] = new Date - d;

d = new Date ;
for (i = count; i-- ;){
r.push.apply(a,b );
//a = [1,2,3] ;
}
r[1] = new Date - d;

alert(r);

It can be concluded that even ancient browsers such as ie6 chrome2 safari 3 firefox 2 are completely victorious in push. Even if some browsers are removed //a = [1,2 ,3]; Comment part. The efficiency is actually better than concat. Such as chrome7 dev and safari 5.