Java判断一个字符串中是否包含某个字符

字符串中是否包含某个字符"/>

Java判断一个字符串中是否包含某个字符

1. indexOf()方法

indexOf()方法来自java.lang.String.indexOf()；
返回值类型为int；

1.1 源代码

//源代码
static int indexOf(char[] source, int sourceOffset, int sourceCount,char[] target, int targetOffset, int targetCount,int fromIndex) {if (fromIndex >= sourceCount) {return (targetCount == 0 ? sourceCount : -1);}if (fromIndex < 0) {fromIndex = 0;}if (targetCount == 0) {return fromIndex;}char first = target[targetOffset];int max = sourceOffset + (sourceCount - targetCount);for (int i = sourceOffset + fromIndex; i <= max; i++) {/* Look for first character. */if (source[i] != first) {while (++i <= max && source[i] != first);}/* Found first character, now look at the rest of v2 */if (i <= max) {int j = i + 1;int end = j + targetCount - 1;for (int k = targetOffset + 1; j < end && source[j]== target[k]; j++, k++);if (j == end) {/* Found whole string. */return i - sourceOffset;}}}return -1;}

1.2 使用方法

public static void main(String[] args){String example = "巴啦啦小魔仙";String son = "巴啦啦";//返回值类型为int//调用indexOf()int result = example.indexOf(son);//返回-1代表不包含if (result == -1){System.out.println(example+"中不包含"+son);//返回非-1代表包含}else {System.out.println(example+"中包含"+son);}
}