c - If C99 lifted "variable declaration at top of block" constraint, why doing so in a "for loop" showing error? -

i read site c99 lifted restriction variables in c must declared @ top of block. tested in program below , indeed true no errors. in th e same program if declare variable in first statement of for loop, error:

'for' loop initial declarations allowed in c99 mode|

two things here. since indeed allowed declare variables in middle of program,as did i, why not allowed in for loop statement? , second, if compiler (codeblocks/gcc) not in c99 mode already, why didn't error when declared variables in middle instead of top?

#include <stdio.h>  int main (void) {   //proof initialization in middle works (for i)   printf("enter\n");   char string[20];   scanf("%s", string);   int i=20;   printf("%s,%i", string, i);   //proved works    for(int j=0; j<10; j++) //this not allowed     printf("%d\n", j); } 

by default gcc compiles code own "dialect" extension of c89. idea new code , learning c nowadays pass more modern , standardized version of language. unfortunately implementation of c11 isn't yet complete, you'd have stick c99 moment using -std=c99.

the gcc online documentation has information on different dialects of c implement.

an alternative compiler clang c99 default. experience better suited beginners because diagnostics bit more user friendly gcc's.