如何判断一个字符串中是否包含另一个字符串？
String ? a ? = ? "HelloWorld";
String ? b ? = ? "oWor";
如何符合判断a中是否包含b？
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如果? a.indexOf(b)> =0?? ?或者?????? a.indexOf(b)!=-1? 就说明包含?
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public ? class ? Text4 ? {?
????????
??????? public ? static ? void ? main ? (String[] ? args) ? {
? ? ? ? String ? a ? = ? "HelloWorld";
??????? String ? b ? = ? "oWor";
???????? System.out.println(a.indexOf(b));
? ? ? ? }
? ? ? ?
}
输出 ? 4 ? ?
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如果不包含输入为 ? -1
public ? int ? indexOf(String ? str)
Returns ? the ? index ? within ? this ? string ? of ? the ? first ? occurrence ? of ? the ? specified ? substring. ? The ? integer ? returned ? is ? the ? smallest ? value ? k ? such ? that: ?
? this.startsWith(str, ? k)
?
is ? true. ?
Parameters:
str ? - ? any ? string. ?
Returns:
if ? the ? string ? argument ? occurs ? as ? a ? substring ? within ? this ? object, ? then ? the ? index ? of ? the ? first ? character ? of ? the ? first ? such ? substring ? is ? returned; ? if ? it ? does ? not ? occur ? as ? a ? substring, ? -1 ? is ? returned.
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