endl與\n的區別

看C++Primer的時候看到的，而後去百度了一下；

比較明白的解釋：

一、區別在於:
\n只表明換行的轉義字符
endl除了表明換行，還緊跟着清出緩衝槽

二、接下來咱們看一下具體內容的辨析：
要明白\n和endl的區別，首先要明白一個概念：
輸出流。
目前輸出流的類型不少，有對文件做爲目標輸出的，有對顯示屏（Console間接輸出）進行輸出的。也有輸出到其餘抽象結構的。

cout的意思是console-output：控制檯輸出.
可是它的機制還遠沒有咱們想的那麼簡單，<<後面跟着寫什麼就直接輸出到屏幕什麼？
不是這樣的。

就拿cout<<"Hi,zw.\n"<<endl;

來講，cout表明後面的內容輸出到控制檯的一個緩衝槽，而不是控制檯（黑屏幕的那個）.

緩衝槽在什麼狀況下會把緩衝槽的內容輸出到控制檯的【屏幕界面】呢？
當遇到endl或者其餘fflush之類的命令或函數時，緩衝槽裏的內容會按照順序輸出到控制檯，再由控制檯進行轉意字符的識別打印。

endl和\n的區別是：

\n在控制檯裏被翻譯爲【換行】
endl在控制檯裏也被翻譯成【換行】

但endl還在緩衝槽這個部分有個功能：清槽，把緩衝槽裏的內容輸出到控制檯。

爲何平時幾乎沒有任何區別呢？
由於緩衝槽即便不用endl,只要遇到另外一行表達式，通常也會自動清槽。

只要程序不蹦，仍是沒什麼區別的，萬一程序崩潰，\n可能會留在緩衝區裏；

貼兩段代碼（及其彙編）：

#include <iostream>
using namespace std;
int main()
{
	cout<<"a"<<endl;
	return 0; 
}

	.file	"\316\264\303\374\303\3731.cpp"
.lcomm __ZStL8__ioinit,1,1
	.def	___main;	.scl	2;	.type	32;	.endef
	.section .rdata,"dr"
LC0:
	.ascii "a\0"
	.text
	.globl	_main
	.def	_main;	.scl	2;	.type	32;	.endef
_main:
LFB971:
	.cfi_startproc
	leal	4(%esp), %ecx
	.cfi_def_cfa 1, 0
	andl	$-16, %esp
	pushl	-4(%ecx)
	pushl	%ebp
	.cfi_escape 0x10,0x5,0x2,0x75,0
	movl	%esp, %ebp
	pushl	%ecx
	.cfi_escape 0xf,0x3,0x75,0x7c,0x6
	subl	$20, %esp
	call	___main
	movl	$LC0, 4(%esp)
	movl	$__ZSt4cout, (%esp)
	call	__ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc
	movl	$__ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_, (%esp)
	movl	%eax, %ecx
	call	__ZNSolsEPFRSoS_E
	subl	$4, %esp
	movl	$0, %eax
	movl	-4(%ebp), %ecx
	.cfi_def_cfa 1, 0
	leave
	.cfi_restore 5
	leal	-4(%ecx), %esp
	.cfi_def_cfa 4, 4
	ret
	.cfi_endproc
LFE971:
	.def	___tcf_0;	.scl	3;	.type	32;	.endef
___tcf_0:
LFB981:
	.cfi_startproc
	pushl	%ebp
	.cfi_def_cfa_offset 8
	.cfi_offset 5, -8
	movl	%esp, %ebp
	.cfi_def_cfa_register 5
	subl	$8, %esp
	movl	$__ZStL8__ioinit, %ecx
	call	__ZNSt8ios_base4InitD1Ev
	leave
	.cfi_restore 5
	.cfi_def_cfa 4, 4
	ret
	.cfi_endproc
LFE981:
	.def	__Z41__static_initialization_and_destruction_0ii;	.scl	3;	.type	32;	.endef
__Z41__static_initialization_and_destruction_0ii:
LFB980:
	.cfi_startproc
	pushl	%ebp
	.cfi_def_cfa_offset 8
	.cfi_offset 5, -8
	movl	%esp, %ebp
	.cfi_def_cfa_register 5
	subl	$24, %esp
	cmpl	$1, 8(%ebp)
	jne	L4
	cmpl	$65535, 12(%ebp)
	jne	L4
	movl	$__ZStL8__ioinit, %ecx
	call	__ZNSt8ios_base4InitC1Ev
	movl	$___tcf_0, (%esp)
	call	_atexit
L4:
	leave
	.cfi_restore 5
	.cfi_def_cfa 4, 4
	ret
	.cfi_endproc
LFE980:
	.def	__GLOBAL__sub_I_main;	.scl	3;	.type	32;	.endef
__GLOBAL__sub_I_main:
LFB982:
	.cfi_startproc
	pushl	%ebp
	.cfi_def_cfa_offset 8
	.cfi_offset 5, -8
	movl	%esp, %ebp
	.cfi_def_cfa_register 5
	subl	$24, %esp
	movl	$65535, 4(%esp)
	movl	$1, (%esp)
	call	__Z41__static_initialization_and_destruction_0ii
	leave
	.cfi_restore 5
	.cfi_def_cfa 4, 4
	ret
	.cfi_endproc
LFE982:
	.section	.ctors,"w"
	.align 4
	.long	__GLOBAL__sub_I_main
	.ident	"GCC: (GNU) 4.8.1"
	.def	__ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc;	.scl	2;	.type	32;	.endef
	.def	__ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_;	.scl	2;	.type	32;	.endef
	.def	__ZNSolsEPFRSoS_E;	.scl	2;	.type	32;	.endef
	.def	__ZNSt8ios_base4InitD1Ev;	.scl	2;	.type	32;	.endef
	.def	__ZNSt8ios_base4InitC1Ev;	.scl	2;	.type	32;	.endef
	.def	_atexit;	.scl	2;	.type	32;	.endef

#include <iostream>
using namespace std; 
int main()
{
	cout<<"a"<<"\n";
	return 0; 
}

	.file	"\316\264\303\374\303\3732.cpp"
.lcomm __ZStL8__ioinit,1,1
	.def	___main;	.scl	2;	.type	32;	.endef
	.section .rdata,"dr"
LC0:
	.ascii "a\0"
LC1:
	.ascii "\12\0"
	.text
	.globl	_main
	.def	_main;	.scl	2;	.type	32;	.endef
_main:
LFB971:
	.cfi_startproc
	pushl	%ebp
	.cfi_def_cfa_offset 8
	.cfi_offset 5, -8
	movl	%esp, %ebp
	.cfi_def_cfa_register 5
	andl	$-16, %esp
	subl	$16, %esp
	call	___main
	movl	$LC0, 4(%esp)
	movl	$__ZSt4cout, (%esp)
	call	__ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc
	movl	$LC1, 4(%esp)
	movl	%eax, (%esp)
	call	__ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc
	movl	$0, %eax
	leave
	.cfi_restore 5
	.cfi_def_cfa 4, 4
	ret
	.cfi_endproc
LFE971:
	.def	___tcf_0;	.scl	3;	.type	32;	.endef
___tcf_0:
LFB976:
	.cfi_startproc
	pushl	%ebp
	.cfi_def_cfa_offset 8
	.cfi_offset 5, -8
	movl	%esp, %ebp
	.cfi_def_cfa_register 5
	subl	$8, %esp
	movl	$__ZStL8__ioinit, %ecx
	call	__ZNSt8ios_base4InitD1Ev
	leave
	.cfi_restore 5
	.cfi_def_cfa 4, 4
	ret
	.cfi_endproc
LFE976:
	.def	__Z41__static_initialization_and_destruction_0ii;	.scl	3;	.type	32;	.endef
__Z41__static_initialization_and_destruction_0ii:
LFB975:
	.cfi_startproc
	pushl	%ebp
	.cfi_def_cfa_offset 8
	.cfi_offset 5, -8
	movl	%esp, %ebp
	.cfi_def_cfa_register 5
	subl	$24, %esp
	cmpl	$1, 8(%ebp)
	jne	L4
	cmpl	$65535, 12(%ebp)
	jne	L4
	movl	$__ZStL8__ioinit, %ecx
	call	__ZNSt8ios_base4InitC1Ev
	movl	$___tcf_0, (%esp)
	call	_atexit
L4:
	leave
	.cfi_restore 5
	.cfi_def_cfa 4, 4
	ret
	.cfi_endproc
LFE975:
	.def	__GLOBAL__sub_I_main;	.scl	3;	.type	32;	.endef
__GLOBAL__sub_I_main:
LFB977:
	.cfi_startproc
	pushl	%ebp
	.cfi_def_cfa_offset 8
	.cfi_offset 5, -8
	movl	%esp, %ebp
	.cfi_def_cfa_register 5
	subl	$24, %esp
	movl	$65535, 4(%esp)
	movl	$1, (%esp)
	call	__Z41__static_initialization_and_destruction_0ii
	leave
	.cfi_restore 5
	.cfi_def_cfa 4, 4
	ret
	.cfi_endproc
LFE977:
	.section	.ctors,"w"
	.align 4
	.long	__GLOBAL__sub_I_main
	.ident	"GCC: (GNU) 4.8.1"
	.def	__ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc;	.scl	2;	.type	32;	.endef
	.def	__ZNSt8ios_base4InitD1Ev;	.scl	2;	.type	32;	.endef
	.def	__ZNSt8ios_base4InitC1Ev;	.scl	2;	.type	32;	.endef
	.def	_atexit;	.scl	2;	.type	32;	.endef

本弱彙編還在學= = 因此不少看不懂=- =~

等能看懂了，再回來研究研究