syntax and semantic errors

Question

What is the difference in between lexical, syntax and semantic errors?

Please give appropriate example also.

Answer 1

Lexical error: Error while identifying lexemes. Like inz a; instead of int a;.
Syntax error: Error in the syntax of some construct. Like printf 30; instead of printf("30");
Semantic error: Error in the meaning of the statement. Like, you have evaluated area of triangle as 2L*B. They might not be detected by compilers.

Comments

lvalue error is a semantic error not syntax error.

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yes L value is semantic error but not syntax. And your lexical error example is not correct because for " inz a" inz will not create lex error but it will be treated as a token whose lexeme is of type identifier. But

int 1ax

is lex error as here 1ax is not matching with RE of identifier nor with  RE of number.

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Error while identifying lexemes. Like inz  a; 

it is right ? i think intz a; is valid token  no lexical error .it is sytax error 

@Bikram 

Answer 2

Lexical errors are those illegal string, unmatched symbols, length of the boundaries are exceeding.

syntax errors are those missing operand, missing left parenthesis, missing right parenthesis etc.

semantic errors are those type checking does not matches, scope of the functions does not found and type conversion is not happend like this.

But when comparing the three phases with each other the most errors occured in syntax phase.