c - Parsing a string in C

Question

I want to parse a string and do some checks on the last character of the string. For example:

char *name = "angela";

int i;
for(i = 0; i <= strlen(name); i++) {
    if(name[i] == 'a' && i == strlen(name)) {
        *do something here*;
     }
}

I tried this but nothing happens. Why won't this work?

Answer 1

Change:

for(i = 0; i <= strlen(name); i++) {
    if(name[i] == 'a' && i == strlen(name)) {

to:

for(i = 0; i < strlen(name); i++) {
    if(name[i] == 'a' && i == strlen(name) - 1) {

Reason: the first character in a C string, s, has index 0, and the last character has index strlen(s) - 1, for a total of strlen(s) characters.

Answer 2

您可以像这样检查字符串的最后一个字符（无需使用循环）：

char *name = "angela";
if(strlen(name)>0)//do the check below only if the string is not empty
if(name[strlen(name)-1]=='a')
{
    //do something here
}

Answer 3

函数 strlen 返回一个字符串的实际长度，而不是它的最后一个索引。在您的示例“angela”中，strlen 将返回 6，但此字符数组的最后一个索引是 5。所以您必须使用：

if(name[i] == 'a' && i == strlen(name) -1)