1、String.valueOf(int i)
2、Integer.toString(int i)
3. I+"; //i is of type int.
The efficiency order of the three methods is:
Integer.tostring (int I) > string.valueof (int I) > I+";
Code test:
Public static void main(String[] args) {
int[]int arr = new int[ 1000000]；
String[] strArr 1 = new string [1000000]; //To be fair, define three arrays respectively.
String[] strArr2 = new string [1000000];
String[] strArr3 = new string [1000000];
//assignment
long t 1 = system . current time millis()；
for(int I = 0； I< 1000000; i++){
intArr[I]= I+ 1；
}
long T2 = system . current time millis()；
for(int I = 0； I< 1000000; i++){
strarr 1[I]= string . value of(intArr[I])；
}
long T3 = system . current time millis()；
for(int I = 0； I< 1000000; i++){
strarr 2[I]= integer . tostring(intArr[I])；
}
long T4 = system . current time millis()；
for(int I = 0； I< 1000000; i++){
strarr 3[I]= intArr[I]+" "；
}
long t5 = system . current time millis()；
system . out . println(" t 1 = "+t 1 ")；
system . out . println(" T2 = "+T2 ")；
system . out . println(" T3 = "+T3)；
system . out . println(" T4 = "+T4)；
system . out . println(" t5 = "+t5 ")；
System.out.println ("assignment:"+(t2-t1));
system . out . println(" string . value of(I):"+(T3-T2))；
system . out . println(" integer . tostring(I):"+(T4-T3))；
system . out . println(" I+\ " \ ":"+(t5-T4))；
}
My test results are:
t 1 = 1298798872078
t2 = 1298798872093
t3 = 1298798872656
t4 = 1298798873000
t5 = 129879887367 1
Distribution: 15
String.valueOf(i):563
Integer.toString(i):344
i+"":67 1