字符串拼接的几种方式

字符串拼接的几种方式

博客分类： java 基础

java 循环 字符串  

工作中经常要把数组拼接成字符串 如数组【a, b, c】变成 字符串“a, b, c”

那么可以采用下面几种方式：

 

 

String[] array = { "1254", "2571", "3389", "6543" };
int Len = array.length;
StringBuilder sb = new StringBuilder(Len * 2);
boolean first = true;
for (String str : array) {
    if (first)
        first = false;
    else
        sb.append(",");

    sb.append(str);
}

String[] array = { "1254", "2571", "3389", "6543" };
int Len = array.length;
StringBuilder sb = new StringBuilder(Len * 2); 
boolean first = true;
for (String str : array) {
	if (first)
		first = false;
	else
		sb.append(",");

	sb.append(str);
}

 

 

String[] array = { "1254", "2571", "3389", "6543" };
int i = 0, Len = array.length;
StringBuilder sb = new StringBuilder(Len * 2);
sb.append(array[i++]);
while (i < Len) {
    sb.append(", ").append(array[i++]);
}

String[] array = { "1254", "2571", "3389", "6543" };
int i = 0, Len = array.length;
StringBuilder sb = new StringBuilder(Len * 2);
sb.append(array[i++]);
while (i < Len) {
    sb.append(", ").append(array[i++]);
}

 

 

String[] array = { "1254", "2571", "3389", "6543" };
int Len = array.length;
StringBuilder sb = new StringBuilder(Len * 2);
sb.append(array[--Len]);
while (Len != 0) {
    sb.append(", ").append(array[--Len]);
}
System.out.println(sb.toString());

String[] array = { "1254", "2571", "3389", "6543" };
int Len = array.length;
StringBuilder sb = new StringBuilder(Len * 2);
sb.append(array[--Len]);
while (Len != 0) {
	sb.append(", ").append(array[--Len]);
}
System.out.println(sb.toString());

 
结果如图：