《Programming Abstractions In C》学习第50天，p123-p126，总结如下：

一、技术总结

1.notaion

这也是一个在计算机相关书籍中出现的词，但有时却不是那么好理解，因为它可以指代很多对象，这里做一个记录。示例：p124。

In C, you can use any character array to hold string data.

or, more compactly,

<pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="c" cid="n106" mdtype="fences" style="box-sizing: border-box; overflow: visible; font-family: var(--monospace); font-size: 0.9em; display: block; break-inside: avoid; text-align: left; white-space: normal; background-image: inherit; background-position: inherit; background-size: inherit; background-repeat: inherit; background-attachment: inherit; background-origin: inherit; background-clip: inherit; background-color: rgb(248, 248, 248); position: relative !important; border: 1px solid rgb(231, 234, 237); border-radius: 3px; padding: 8px 4px 6px; margin-bottom: 15px; margin-top: 15px; width: inherit; color: rgb(51, 51, 51); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">char str[6] = "hello";</pre>

If you use array notation, the standar idion for processing every character in a string looks like this:

<pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="C" cid="n108" mdtype="fences" style="box-sizing: border-box; overflow: visible; font-family: var(--monospace); font-size: 0.9em; display: block; break-inside: avoid; text-align: left; white-space: normal; background-image: inherit; background-position: inherit; background-size: inherit; background-repeat: inherit; background-attachment: inherit; background-origin: inherit; background-clip: inherit; background-color: rgb(248, 248, 248); position: relative !important; border: 1px solid rgb(231, 234, 237); border-radius: 3px; padding: 8px 4px 6px; margin-bottom: 15px; margin-top: 15px; width: inherit; color: rgb(51, 51, 51); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">for (int i = 0; str[i] != '\0'; i++) {

printf("i=%d\n", str1[i]);

}</pre>

在这里，“notation”以理解为“the activity of representing sth by a special system of marks or character”，即“notation”表示的是一种“标记方法”、“表示方法”。

2.字符串用法示例

<pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="C" cid="n111" mdtype="fences" style="box-sizing: border-box; overflow: visible; font-family: var(--monospace); font-size: 0.9em; display: block; break-inside: avoid; text-align: left; white-space: normal; background-image: inherit; background-position: inherit; background-size: inherit; background-repeat: inherit; background-attachment: inherit; background-origin: inherit; background-clip: inherit; background-color: rgb(248, 248, 248); position: relative !important; border: 1px solid rgb(231, 234, 237); border-radius: 3px; padding: 8px 4px 6px; margin-bottom: 15px; margin-top: 15px; width: inherit; color: rgb(51, 51, 51); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">#include <stdio.h>

// 统计字符串中的空格(space):数组版
static int CountSpaces(char str[]) {
int i, nSpaces;

nSpaces = 0;
for (i = 0; str[i] != '\0'; i++) {
if (str[i] == ' ') {
nSpaces++;
}
}
return nSpaces;
}

// 统计字符串中的空格(space)：指针版
static int CountSpaces1(char *str) {
int nSpaces;
char *cp;

nSpaces = 0;
for (cp = str; cp != '\0'; cp++) {
if (cp == ' ') {
nSpaces++;
}
}
return nSpaces;

}

int main() {
// 方式一：declare and initialize a string "hello"
char str1[6] = {'h', ' ', 'l', ' ', 'o', '\0'};
// 遍历字符串
for (int i = 0; str1[i] != '\0'; i++) {
printf("i=%d\n", str1[i]);
}

// 方式二：更紧凑(compactly)
char str2[6] = "hello";

// 统计字符串中的空格
int n;
n = CountSpaces(str1);
printf("\nthe number of spaces in string is: %d\n", n); // 2

// 统计字符串中的空格
int n1;
n1 = CountSpaces1(str1);
printf("\nthe number of spaces in string is: %d\n", n1); // 2

}
</pre>

二、英语总结

1.perfectively什么意思？

答：perfect是“完美的”之意，但是perfectly翻译的时候直接翻译成"完美地"却不大合适。应该翻译成"adv. perfectly can alse mean very or compeletly"（很，非常）更好，当然，其实这个意思也是“in a perfect way”。

2.likelihood什么意思？

答：u.the chance than sth will happen(可能性)，同义词：possibility。

三、参考资料

1. 编程

(1)Eric S.Roberts，《Programming Abstractions in C》：https://book.douban.com/subject/2003414

2. 英语

(1)Etymology Dictionary：https://www.etymonline.com

(2) Cambridage Dictionary：https://dictionary.cambridge.org

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Programming abstractions in C阅读笔记：p123-p126