Three methods and efficiency for clearing stringbuilder

Three methods and efficiency for clearing stringbuilder   We know that stringbuilder is used for frequent String concatenation. the append method is much more efficient than the string + = method, but sometimes you do not know how to clear stringbuilder because it does not have the clear or empty method. So what method is used? I searched the internet for three methods. 1. Remove example: stringbuilder val = new stringbuilder (); Val. append (".... "); Val. remove (0, Val. length); // clear 2. Replace stringbuilder val = new stringbuilder (); Val. append (".... "); Val. replace (Val. tostring (), ""); // clear 3. Length stringbuilder val = new stringbuilder (); Val. append (".... "); Val. length = 0; // empty the efficiency of the three methods is simply tested, and the average value of the three methods is tested: datetime dt = datetime. now; const int testnum= 1000000; stringbuilde R strbuilder = new stringbuilder (); For (INT I = 0; I <testnum; I ++) {strbuilder. append ("test"); strbuilder. remove (0, strbuilder. length);} console. writeline ("rsemove:" + (datetime. now-Dt ). ticks); first, time used: 366687; second, time used: 1186734; third, time used: 180010, visible, or length used, which is more efficient. This test is my simple test. If you have different opinions, please leave a message to study and discuss it together!